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Indian Journal of Biotechnology

 

Special Issue on
Microbial and Industrial Biotechnology

 

VOLUME 2

NUMBER 3

JULY 2003

 

 

CONTENTS

Autolysis of Penicillium chrysogenum—A holistic approach

293

István Pócsi, Tünde Pusztahelyi, László Sámi and Tamás Emri

 

 

 

Advances in pest control: The role of Bacillus thuringiensis

302

S R Prabagaran, K R Rupesh, S J Nimal, S Sudha Rani and S Jayachandran

 

 

 

Microbial secondary metabolites production and strain improvement

322

J Barrios-González, F J Fernández and A Tomasini

 

 

 

Sources, properties and applications of microbial therapeutic enzymes

334

A Sabu

 

 

 

Mycobacterial b-lactamases: An overview

342

K Madhavan Nampoothiri

 

 

 

Production of heterologous microbial lipases by yeasts

346

Ali Kademi, Byong Lee and Alain Houde

 

 

 

Enzyme behaviour in non-conventional systems

356

Licia M Pera, Mario D Baigori and Guillermo R Castro

 

 

 

Microbial pigments

362

V K Joshi, Devender Attri, Anju Bala and Shashi Bhushan

 

 

 

Microbial transformation of rifamycin: A novel approach to rifamycin derivatives

 370

 A H Jobanputra, G D Patil, R Z Sayyed, A B Chaudhari and S B Chincholkar

 

 

 

Effect of lactic acid bacteria on animal performance

378

Zwi G Weinberg

 

 

 

Applications of microorganisms in food biotechnology

382

J S Pai

 

 

 

Phytoestrogens

387

K S Sebastian and Raghava Varman Thampan

 

   

Biofiltration: An emerging technology

396

Carlos R Soccol, Adenise L Woiciechowski, Luciana P S Vandenberghe, Marlene Soares, Georges Kaskantis Neto and Vanete Thomaz-Soccol

 

 

 

Bioremediation of petroleum hydrocarbon pollution

411

Abu Bakar Salleh, Farinazleen Mohamad Ghazali, Raja Noor Zaliha Abd Rahman and Mahiran Basri

 

 

 

Bioremediation of metalliferous wastes and products using inactivated microbial biomass

426

K M Paknikar, A V Pethkar and P R Puranik

 

 

 

Waste water bioremediation in the pulp and paper industry

444

L Christov and B van Driessel

 

 

 

Role of acidothermophilic autotrophes in bioleaching of mineral sulphide ores

451

Valentina V Umrania

 

 

 

Instructions to Contributors

465


 


Indian Journal of Biotechnology

Vol 2(3), July 2003, pp. 293-301

 

Autolysis of Penicillium chrysogenum—A Holistic Approach

István Pócsi*, Tünde Pusztahelyi, László Sámi and Tamás Emri

Department of Microbiology and Biotechnology, Faculty of Science, University of Debrecen, Egyetem tér 1,

H-4010 Debrecen, Hungary

 

Received 20 January 2003; accepted 20 February 2003

 

 

Despite of its biotechnological significance, the autolysis of filamentous fungi is a poorly studied and understood area of fungal physiology. The autolysis of b-lactam producing fungus, Penicillium chrysogenum shares some similarities with the apoptosis of higher eukaryotes. For example, the biosynthesis and processing of age-related hydrolases were highly regulated in carbon-depleted cultures. The in vivo inhibition of autolytic chitinase activity hindered considerably the disintegration of pelleted structures that are typical of the exponential growth phase. In the absence of conidiation, round-ended “yeast-like” hyphal fragments were the dominant surviving morphological forms, which were characterised with decreasing total respiration, increasing cyanide-resistant respiration, intracellular accumulation of reactive oxygen species (ROS) and declining viability in the autolytic and post-autolytic phases of growth. The term “ageing” was used to describe these physiological changes, and the surviving fragments may undergo oxidative-stress induced programmed cell death. Although variations in oxygen tension and extracellular ROS concentrations are key elements in the initiation of morphological changes, the genomic expression programmes of fungi governing morphological transitions including autolysis are likely to be activated by different kinds of environmental stress and signal transduction pathways. The glutathione (GSH) and ROS metabolisms of P. chrysogenum were influenced by many extrinsic and intrinsic factors in each growth phase studied. As a consequence, no firm correlation was found between the GSH/glutathione disulphide (GSSG) redox status, the intracellular ROS levels and the observed morphological and physiological characteristics of the cells.

 

Keywords: autolysis, apoptosis, ageing, fragmentation, vacuolation, chitinase, respiration

 

 

 

Indian Journal of Biotechnology

Vol 2(3), July 2003, pp. 302-321

 

 

Advances in Pest Control: The Role of Bacillus thuringiensis

S R Prabagaran, K R Rupesh, S J Nimal, S Sudha Rani and S Jayachandran*

Department of Biotechnology, Pondicherry University, Pondicherry 605 014, India

 

Received 9 January 2003; accepted 20 February 2003

 

 

Bacillus thuringiensis (Bt), a popularly known biopesticide, has widest scope in skirmishing diverse species of insects. Numerous reports have appeared on the ecology and distribution of Bt around the world. Characterizing Bt strains based on cry gene contents envisages more on its application potential. In the recent past, organizing the cry gene nomenclature based on protein/nucleotide sequence has overcome many ambiguities that persisted for long. This initiative of the decade has paved way to face the challenges of new additions in cry genes and assigning its phylogenetic position. In vitro evidences on insect mortality are most often not reproducible under field conditions. Therefore, numerous formulations have been developed by various entrepreneurs to combat insect pest menace. In malevolence of all advantages, development of resistance is the greatest threat to Bt industry and environmentalists as well. Though several alternative methods are practiced, it needs enormous effort to really understand the mode of development of resistance and to combat it accordingly. In agrarian and health sector, development of transgenic organisms is the recent trendsetter deserving attention. However, there is a cause for concern in advocating transgenics since the long-term effects of transgenics on the living organisms is not well understood. After weighing the advantages and disadvantages of application of Bt in the environment, it could be concluded that Bt definitely offers best scope in being biodegradable, non-toxic, target specific and most importantly renewable compared to chemical insecticides for the control of insect-pests.

 

Keywords: Bacillus thuringiensis, cry genes, d-endotoxins, insect resistance, formulations, transgenics.

 

 

 

Indian Journal of Biotechnology

Vol 2(3), July 2003, pp. 322-333

 

 

Microbial Secondary Metabolites Production and Strain Improvement

J Barrios-González *, F J Fernández and A Tomasini

Depto de Biotecnología, Universidad Autónoma Metropolitana, Iztapalapa, Apdo Postal 55-535,

México D F 09340, México

 

Received 20 November 2002; accepted 20 February 2003

 

Microbial secondary metabolites are compounds produced mainly by actinomycetes and fungi, usually late in the growth cycle (idiophase). Although antibiotics are the best known secondary metabolites (SM), there are others with an enormous range of other biological activities mainly in fields like: pharmaceutical and cosmetics, food, agriculture and farming. These include compounds with anti-inflammatory, hypotensive, antitumour, anticholesterolemic activities, and also insecticides, plant growth regulators and environmental friendly herbicides and pesticides. These compounds are usually produced by liquid submerged fermentation, but some of these metabolites could be advantageously produced by solid-state fermentation. Today, strain improvement can be performed by two alternative strategies, each having distinct advantages, and in some cases all these approaches can be used in concert to increase production such as classical genetic methods with mutation and random selection or rational selection (including genetic recombination); and molecular genetic improvement methods. The latter can be applied by: amplification of SM biosynthetic genes, inactivation of competing pathways, disruption or amplification of regulatory genes, manipulation of secretory mechanisms and expression of a convenient heterologous protein. It is visualized that in the near future, genomics will also be applied to industrial strain improvement.

 

Keywords: secondary metabolites, new activities, classical and molecular genetic improvement

 

 

 

Indian Journal of Biotechnology

Vol 2(3), July 2003, pp. 334-341

 

 

Sources, Properties and Applications of Microbial Therapeutic Enzymes

A Sabu*

Biotechnology Division, Regional Research Laboratory, Thiruvananthapuram 695 019, India

 

Received 22 January 2003; accepted 20 February 2003

 

 

Enzymes or biocatalysts are produced in the human body from amino acids that the body obtains by digesting food proteins. Enzymes accelerate and control all biochemical processes in the body and in a single second several millions of enzyme mediated chemical reactions occur in a human body. Each enzyme is programmed to carry out one special task. The immense number of enzymes acts as a perfectly matched orchestra to ensure that enormously complex life mechanisms and processes occur in a right direction. Sufficient amount and optimal function of enzymes present in the human body is essential for life and health. Microbial enzymes play a major role in the diagnosis, curing, biochemical investigation and monitoring of many dreaded diseases of the century. Information on this topic is very meagre and thus the present review is an attempt to compile information on the sources, properties and applications of important therapeutic enzymes.

 

Keywords: therapeutic enzymes, glutaminase, asparaginase, enzyme therapy, tumour, biodrug

 

 

 

Indian Journal of Biotechnology

Vol 2(3), July 2003, pp. 342-345

 

 

Mycobacterial b-Lactamases: An Overview

K Madhavan Nampoothiri*

Biotechnology Division, Regional Research Laboratory, Thiruvananthapuram 695 019, India

 

Received 20 January 2003; accepted 21 February 2003

 

 

Despite of four decades of effective chemotherapy, tuberculosis has re-emerged as one of the leading causes of death. Prevention and control of tuberculosis got a great setback by the appearance of multidrug resistant strains of M. tuberculosis. New antibiotic regiments are needed for the treatment of multidrug resistant tuberculosis. b-Lactam antibiotics that inhibit transpeptidase reactions and prevent cell wall assembly in bacteria are the most widely used antimicrobial agents. However, most of the mycobacteria are naturally resistant to b-lactams, presumably because of their extremely hydrophobic cell wall, presence of periplamsic penicillin binding proteins (PPBS) and most importantly the presence of an active b-lactamase. This paper details the various studies on b-lactamases of Mycobacterium and highlights the importance of b-lactamases, in future, for developing an effective drug combination comprising a b-lactam antibiotic in combination with b-lactamase inhibitors.

 

Keywords: Mycobacterium, b-lactamases, penicillin binding proteins

 

 

 

Indian Journal of Biotechnology

Vol 2(3), July 2003, pp. 346-355

 

 

Production of Heterologous Microbial Lipases by Yeasts

Ali Kademi, Byong Lee and Alain Houde*

Agriculture and Agri-Food Canada, Food Research and Development Centre

3600 Casavant Blvd West, St-Hyacinthe, Quebec, Canada, J2S 8E3

 

Received 12 November 2002; accepted 21 February 2003

 

 

Lipases (triacylglycerol lipase, EC 3.1.1.3) catalyse the hydrolysis of triglycerides to di-glycerides, mono-glycerides, glycerol and fatty acids. In non-aqueous media, these enzymes also catalyse esterification, interesterification and transesterification. This versatility makes the lipases potential biocatalysts in many industrial applications. This review describes the recent advances in the use of yeasts as expression systems to produce high levels of recombinant microbial lipases. Some expression systems such as Saccharomyces cerevisiae and Pichia pastoris are reviewed and compared. Also, cell-surface display systems as novel methods to construct whole cell biocatalysts are highlighted.

 

Keywords: microbial lipase, Pichia pastoris, Saccharomyces cerevisiae, expression system

 

 

 

Indian Journal of Biotechnology

Vol 2(3), July 2003, pp. 356-361

 

 

Enzyme Behaviour in Non-conventional Systems

Licia M Pera1, Mario D Baigori1 and Guillermo R Castro2*

1PROIMI, Av. Belgrano y Pasaje Caseros. 4000 MTV Tucumán, Argentina

2Department of Biomedical Engineering, Tufts University. 4 Colby Street, Medford, MA 02155, USA

 

Received 16 November 2002; accepted 21 February 2003

 

 

Most important recent advances in biocatalytic biphasic systems such as aqueous two-phase reactor systems using environmental sensitive polymers, two-phase aqueous-organic systems, reverse micelles, microemulsion-based organogels, and trapped aqueous-organic solvent continuous biphasic reactor are reviewed.

 

Keywords: heterogeneous biphasic system, non-conventional media, aqueous two-phase systems, partitioning, aqueous-organic two-phase systems, trapped aqueous-organic biphasic system, reverse micelles, W/O microemulsions, microemulsion-based gels, extraction systems

 

 

 

Indian Journal of Biotechnology

Vol 2(3), July 2003, pp. 362-369

 

 

Microbial Pigments

V K Joshi*, Devender Attri, Anju Bala and Shashi Bhushan

Department of Post-harvest Technology, Dr Y S Parmar University of Horticulture and Forestry,

Nauni, Solan 173 230, India

 

Received 9 December 2002; accepted 10 February 2003

 

 

The microorganisms such as Monascus, Rhodotorula, Bacillus, Achromobacter, Yarrowia and Phaffia produce a large number of pigments. An ideal pigment-producing microorganism should be capable of using a wide range of C and N sources, have tolerance to pH, temperature and minerals, and give reasonable colour yield. Non-toxic and non-pathogenic nature of pigment-producing microorganisms coupled with easy separation from the cell biomass is stressed. The various advantages of producing pigments from microorganisms include independence from weather conditions, easy and fast growth, colours of different shades and growth on cheap substances. Studies revealed unstable, largely degradable and sensitive to heat, light, acidity and water activity as characteristics of microbial colour. Improvement in stability, safety and solubility can certainly make widespread use of microbial pigments in the food industry.

 

Keywords: microorganisms, pigment, food, toxicity, carotenoid, solid-state fermentation

 

 

 

Indian Journal of Biotechnology

Vol 2(3), July 2003, pp. 370-377

 

 

Microbial Transformation of Rifamycin: A Novel Approach to Rifamycin Derivatives

A H Jobanputra, G D Patil, R Z Sayyed, A B Chaudhari and S B Chincholkar*

School of Life Sciences, North Maharashtra University, P B 80, Jalgaon 425 001, India

 

Received 10 December 2002; accepted 8 April 2003

 

 

Biotransformation of an ansamycin group of antibiotic, rifamycin B (clinically less active) to a more potent antibiotic rifamycin S, involves the action of rifamycin oxidase. The extracellular rifamycin oxidase (RO) from Curvularia lunata offers ease in the process and increased biotransformation potential and yield. Extracellular RO from C. lunata deserves a great future since it shows higher activity and biotransformation potential vis-a-vis intracellular RO from Monocillium and Humicola. Rifamycin S, especially among the derivatives, has been of great commercial significance as a key intermediate for the synthesis of several hundreds of semisynthetic rifamycins. Besides these, rifamycin S has broad-spectrum activity against Brucella, Chlamydia, Haemophilus, Helicobacter pylori, Legionella and Staphylococcus. It has also emerged as an antituberculosis and antileprosy drug. Chemical conversion of rifamycin B against microbial transformation has been discussed with special emphasis on biotransforming systems, characteristics of rifamycin oxidase and factors influencing the production of rifamycin oxidase and biotransformation of rifamycin B to S.

 

Keywords: biotransformation, rifamycin s, rifamycin oxidase, Curvularia lunata, Monocillium and Humicola

 

 

 

Indian Journal of Biotechnology

Vol 2(3), July 2003, pp. 378-381

 

 

Effect of Lactic Acid Bacteria on Animal Performance

Zwi G Weinberg*

Forage Preservation and By-Products Research Unit, Department of Food Science,

the Volcani Center, Bet Dagan, 50250, Israel

 

Received 1 January 2003; accepted 20 February 2003

 

 

Lactic acid bacteria(LAB) which are included in inoculants for silage, sometimes impart beneficial effects, similar to when fed directly, on cattle performance. LABs might interact with rumen microorganisms in such a way that their activity is enhanced and fibre degradability is improved. Another possibility is that LABs produce bacteriocins in the silage which might inhibit detrimental microorganisms, both in the silage and in the rumen.

 

Key words: lactic acid bacteria, ruminants, animal performance, probiotic effects

 

 

 

Indian Journal of Biotechnology

Vol 2(3), July 2003, pp. 382-386

 

 

Applications of Microorganisms in Food Biotechnology

J S Pai*

Department of Food and Fermentation Technology, Institute of Chemical Technology, University of Bombay,

Matunga, Mumbai 400 019, India

 

Received 28 November 2002; accepted 20 February 2003

 

 

Strain improvement of microorganisms in food products has been slow as isolation and mutation are time-consuming and labour-intensive. Hybridization also is slow as unwanted traits have to be bred out. Applications with food related enzymes were the first products of modern biotechnology, followed by organic acids and amino acid production by microorganisms. Food fermentation applications such as fermented dairy products and alcoholic beverages have also shown good possibility for using GMOs for improved fermentation performance and resistance to bacteriophages rather than yield improvement. Improvement in product characteristics including better nutritive quality will be the driving force of future research in food biotechnology.

 

Keywords: genetically engineered microorganisms, acids, enzymes, dairy fermentation, alcoholic fermentation

 

 

 

Indian Journal of Biotechnology

Vol 2(3), July 2003, pp. 387-395

 

 

Phytoestrogens

K S Sebastian and Raghava Varman Thampan*

Rajiv Gandhi Centre for Biotechnology, Thiruvanathapuram 695 014, India

 

Received 10 February 2003; accepted 21 February 2003

 

 

Phytoestrogens are chemical agents, originated from plants, which display structural and functional similarity to 17b estradiol and show both estrogen agonist and antagonistic properties. During recent years phytoestrogens attracted immense public attention as an alternative to estradiol in estrogen replacement therapy for treating postmenopausal women. Epidemiological data have shown a strong correlation between the incidence of hormone dependent diseases and the nature of the diet. Different phytoestrogens exert their biological effects through different mechanisms and through different types of receptors, the expression of which appears to be tissue specific. Though there is considerable amount of epidemiological data indicating the possible health benefits of phytoestrogens, for better utilization of these agents a deeper understanding of the mechanism of action of these estrogens is essential. This will help in the identification of a particular type of phytoestrogen, which can elicit a tissue specific effect under a given clinical condition.

 

Keywords : phytoestrogens, estrogen receptor a, non-activated estrogen receptor, nuclear estrogen receptor II, estrogen receptor activation factor

 

 

 

Indian Journal of Biotechnology

Vol 2(3), July 2003, pp. 396-410

 

 

Biofiltration: An Emerging Technology

Carlos R Soccol1*, Adenise L Woiciechowski1, Luciana P S Vandenberghe1,

Marlene Soares2, Georges Kaskantis Neto1 and Vanete Thomaz-Soccol3

1Biotechnology Processes Laboratory, Department of Chemical Engineering, UFPR,

Federal University of Paraná, P O Box 19011, CEP 81531-970 Curitiba-PR, Brazil

2Federal Center of Technological Education of Paraná, CEFET–PR, Brazil

3Pathology Department, Molecular Parasitology Laboratory, Federal University of Parana,

CEP 81531-970 Curitiba–PR, Brazil

 

Received 20 December 2002; accepted 21 February 2003

 

 

Gas biofiltration is a relatively new technology used to purify contaminated air from volatile organic and inorganic compounds (VOCs and VICs). This biotechnological process is now gaining popularity among industries due to its low cost, operational simplicity, removal efficiency, comprehension, modeling and mainly because it is intrinsically clean, as it reduces or eliminates the need for additional treatment of the end-products. Since 1980s different chemical processes have been utilizing biofiltration with different flow rates, up to 200 thousand m3 hr-1. Technologies considered being forms of biological gas purification include bioscrubbers, biotrickling filters and biofilters, operating with the same fundamental mechanisms of biodegradation. Biofilters, subject of this review, can be regarded as solid fermenters. The polluted gas is forced to flow through a bed packed support on which microorganisms are immobilized or attached as a biofilm. As a biological purification process, it is based on the ability of microorganisms to degrade organic and inorganic compounds, and their complete oxidation to generate energy. This review describes and evaluates some techniques, apparatus and support media used for biofiltration of gases, focusing industrial applications. The encapsulation of microbial cells has also been considered.

 

Keywords: biofiltration, solid state fermentation, cell immobilization, biofilter, volatile organic and inorganic compounds

 

 

 

Indian Journal of Biotechnology

Vol 2(3), July 2003, pp. 411-425

 

 

Bioremediation of Petroleum Hydrocarbon Pollution

Abu Bakar Salleh*, Farinazleen Mohamad Ghazali, Raja Noor Zaliha Abd Rahman and Mahiran Basri

Enzyme and Microbial Technology Research, Faculty of Science and Environmental Studies,

Universiti Putra Malaysia, 43400 UPM Serdang, Malaysia

 

Received 13 November 2002; accepted 21 February 2003

 

 

Uncontrolled and catastrophic releases of petroleum pose ecological and environmental repercussions as a lot of hydrocarbon components are toxic and persistent in terrestrial and aquatic environments. Several physico-chemical methods of decontaminating the environment have been established and employed. Biological degradation, a safe, effective and an economic alternative method, is a process of decay initiated by biological agents, specifically in this case by microorganisms. Bioremediation refers to site restoration through the removal of organic contaminants by microorganisms. Biodegradation of hydrocarbons is largely carried out by diverse bacterial populations, which are ubiquitously distributed in the environment. The most commonly reported genera of hydrocarbon-degraders include Pseudomonas, Acinetobacter, Nocardia, Vibrio and Achromobacter. The factors, that influence the rates of microbial degradation of hydrocarbons, include temperature, pH, salinity, oxygen, nutrients, and physical and chemical composition of petroleum. Due to the complexity of crude oil, biodegradation involves the interaction of many different microbial species. It could be attributed to the effects of synergistic interactions among members of the consortium.

 

Keywords: bioremediation, petroleum, hydrocarbon, biodegradation, parameters

 

 

 

Indian Journal of Biotechnology

Vol 2(3), July 2003, pp. 426-443

 

 

Bioremediation of Metalliferous Wastes and Products using Inactivated Microbial Biomass

K M Paknikar1*, A V Pethkar1 and P R Puranik2

1Division of Microbial Sciences, Agharkar Research Institute, G G Agarkar Road, Pune- 411 004, India

2Department of Biotechnology, School of Life Sciences, North Maharashtra University

P O Box 80, Jalgaon 425 001, India

 

Received 12 November 2002; accepted 21 February 2003

 

 

In a developing country like India, the rush for rapid industrial development coupled with lack of awareness about metal toxicity has become a serious concern to environmentalists. Some technologies, which are used in developed countries for detoxifying metals from industrial effluents, cannot be used in India due to economic constraints. Therefore, there is an urgent need for developing an economical and environment-friendly technology. At the same time, it is essential to prevent the loss of metals through the effluents. The ‘Metal Biosorption’ process provides a promising alternative method for economical recovery of metals.

 

Keywords: bioremediation, metals, biosorption, biomass

 

 

 

Indian Journal of Biotechnology

Vol 2(3), July 2003, pp. 444-450

 

 

Waste Water Bioremediation in the Pulp and Paper Industry

L Christov1,2,* and B van Driessel1

1Sappi Biotechnology Laboratory, Department of Microbiology, Biochemistry and Food Science,

University of the Free State, P O Box 339, 9300 Bloemfontein, South Africa

2Sappi Forest Products Technology Centre, Sappi Management Services, P O Box 3252, 1560 Springs, South Africa

 

Received 13 November 2002; accepted 20 February 2003

 

 

Effluents from the pulp and paper industry contain chromophoric compounds and can be partly mutagenic and inhibitory to aquatic biosystems. The presence of various pollutants produced during pulp and paper manufacturing necessitates the need for waste water pretreatment prior to discharge. Of all the methods investigated, bioremediation specifically holds promise in solving environmental problems in a cost-effective way. White-rot fungi have ability to process a variety of pollutants efficiently, however, development of suitable cultivation procedures has delayed industrial application. These and other issues affecting bioremediation of industrial wastewater, with special reference to application thereof in the pulp and paper industry, are reviewed in this paper.

 

Key words: bioremediation, waste water, pulp and paper industry, white-rot fungi, decolourization

 

 

 

Indian Journal of Biotechnology

Vol 2(3), July 2003, pp. 451-464

 

 

Role of Acidothermophilic Autotrophs in
Bioleaching of Mineral Sulphide Ores

Valentina V Umrania*

Microbiology Department, MVM Science and Home Science College, Kalawad Road, Rajkot 360 002, India

 

Received 13 January 2003; accepted 20 February 2003

 

 

Living organisms synthesize a wide array of enzymes, which catalyze a myriad of reactions both inside and outside the cell. The acidothermophilic iron-oxidizing bacteria represent a group of obligately autotrophic chemolithotrophs. They include mesophilic Thiobacillus thiooxidans, Leptospirillum ferrooxidans and thermophilic bacteria such as Sulfolobus and Acidianus species. Several studies have shown the importance and feasibility of microbiological prospecting for sulphide ore deposits. Acidothermophilic autotrophic bacteria are now considered as an ideal source to exploit more unusual commercial applications of Geo-biotechnology, especially for metal and mining industry. The mining of copper, uranium, molybdenum, zinc, silver, gold, etc, from their sulphide ores is successfully possible with these microbes. The predominant characteristic of chemolithotrophs is their ability to survive and flourish in a completely inorganic aqueous environment with a supply of oxidizable substrate and CO2. A number of different species have now been isolated from high temperature regions and their potential for the rapid leaching of some ores. The ability of such isolates to tolerate high concentration of toxic heavy metals makes them excellent tools for accumulation and/or for biochemical transformation of metals. The outline of such applications are described in the present review.

 

Keywords: acidothermophiles, bioleaching, mineral sulphide ores, bio-oxidation, chemolithotrophs

 

 

 

Author Index

 

 

Abd. Rahman R N Z 411

Attri D                        362

 

Baigori M D               356

Bala A                         362

Barrios-González J     322

Basri M                      411

Bhushan S                   362

 

Castro G R                 356

Chaudhari A B            370

Chincholkar S B          370

Christov L                  444

 

Emri T                        293

 

Fernández F J             322

 

Ghazali F M               411

 

Houde A                     346

 

Jayachandran S               302

Jobanputra A H             370

Joshi V K                       362

 

Kademi A                       346

 

Lee B                              346

 

Nampoothiri K.M          342

Neto G K                       396

Nimal S J                        302

 

Pai J S                             382

Paknikar K M                426

Patil G D                        370

Pera L M                        356

Pethkar A V                   426

Pócsi I                            293

Prabagaran S R               302

Puranik P R                    426

Pusztahelyi T                 293

 

 

Rani S S                          302

Rupesh K R                   302

 

Sabu A                            334

Salleh A B                      411

Sámi L                            293

Sayyed R Z                    370

Sebastian K S                 387

Soares M                        396

Soccol C R                      396

 

Thampan R V                 387

Thomaz-Soccol V           396

Tomasini A                    322

 

Umrania V V                  451

 

Van Driessel B                444

Vandenberghe L P S       396

 

Weinberg Z G                 378

Woiciechowski A L        396