Extremophiles: radiation resistance microbial reserves and therapeutic implications.

Micro-organisms with the ability to survive in extreme environmental conditions are known as 'extremophiles'. Currently, extremophiles have caused a sensation in the biotechnology/pharmaceutical industries with their novel compounds, known as 'extremolytes'. The potential applications of extremolytes are being investigated for human therapeutics including anticancer drugs, antioxidants, cell cycle-blocking agents, anticholesteric drugs, etc. It is hypothesized that the majority of ultraviolet radiation (UVR)-resistant micro-organisms can be used to develop anticancer drugs to prevent skin damage from UVR. The metabolites from UVR-resistant microbes are a great source of potential therapeutic applications in humans. This article aims to discuss the potentials of extremolytes along with their therapeutic implications of UVR extremophiles. The major challenges of therapeutic development using extremophiles are also discussed.

Mutagenesis and analysis of mold Aspergillus niger for extracellular glucose oxidase production using sugarcane molasses.

Aspergillus niger ORS-4.410, a mutant of A. niger ORS-4, was generated by repeated ultraviolet (UV) irradiation. Analysis of the UV treatment dose on wild-type (WT) A. niger ORS-4, conidial survival, and frequency of mutation showed that the maximum frequency of positive mutants (25.5%) was obtained with a 57% conidial survival rate after the second stage of UV irradiation. The level of glucose oxidase (GOX) production from mutant A. niger ORS-4.410 thus obtained was 149% higher than that for WT strain A. niger ORS-4 under liquid culture conditions using hexacyanoferrate (HCF)-treated sugarcane molasses (TM) as a cheaper carbohydrate source. When subcultured monthly for 24 mo, the mutant strain had consistent levels of GOX production (2.62 +/- 0.51 U/mL). Mutant A. niger ORS-4.410 was markedly different from the parent strain morphologically and was found to grow abundantly on sugarcane molasses. The mutant strain showed 3.43-fold increases in GOX levels (2.62 +/- 0.51 U/mL) using HCF-TM compared with the crude form of cane molasses (0.762 +/- 0.158 U/mL).

Bioconversion of grape must into modulated gluconic acid production by Aspergillus niger ORS-4.410.

AIMS: Analysis of regulators for modulated gluconic acid production under surface fermentation (SF) condition using grape must as the cheap carbohydrate source, by mutant Aspergillus niger ORS-4.410. Replacement of conventional fermentation condition by solid-state surface fermentation (SSF) for semi-continuous production of gluconic acid by pseudo-immobilization of A. niger ORS-4.410. METHODS AND RESULTS: Grape must after rectification was utilized for gluconic acid production in batch fermentation in SF and SSF processes using mutant strain of A. niger ORS-4.410. Use of rectified grape must led to the improved levels of gluconic acid production (80-85 g l(-1)) in the fermentation medium containing 0.075% (NH4)2HPO4; 0.1% KH2PO4 and 0.015% MgSO4.7H2O at an initial pH 6.6 (+/-0.1) under surface fermentation. Gluconic acid production was modulated by incorporating the 2% soybean oil, 2% starch and 1% H2O2 in fermentation medium at continuously high aeration rate (2.0 l min(-1)). Interestingly, 95.8% yield of gluconic acid was obtained when A. niger ORS-4.410 was pseudo-immobilized on cellulose fibres (bagasse) under SSF. Four consecutive fermentation cycles were achieved with a conversion rate of 0.752-0.804 g g(-1) of substrate into gluconic acid under SSF. CONCLUSIONS: Use of additives modulated the gluconic acid production under SF condition. Semi-continuous production of gluconic acid was achieved with pseudo-immobilized mycelia of A. niger ORS-4.410 having a promising yield (95.8%) under SSF condition. SIGNIFICANCE AND IMPACT OF THE STUDY: The bioconversion of grape must into modulated gluconic acid production under SSF conditions can further be employed in fermentation industries by replacing the conventional carbohydrate sources and expensive, energy consuming fermentation processes.

A microcosm study on bioremediation of p-nitrophenol-contaminated soil using Arthrobacter protophormiae RKJ100.

p-Nitrophenol (PNP), a toxic nitroaromatic compound, can build up in soils due to extensive usage of nitrophenolic pesticides and hence needs to be removed. Arthrobacter protophormiae RKJ100, a PNP-degrading organism, was used in this work to study factors affecting its growth, and then evaluated for its capacity to degrade PNP in soil microcosms. Molasses (10%) treated with 0.1% potassium hexacyanoferrate was found to be a suitable and cheap carbon source for inoculum preparation. Induction studies showed that PNP depletion was quicker when cells were induced by pre-exposure to PNP. The efficiency of PNP degradation in soil by strain RKJ100 was seen to be dependent on pH, temperature, initial PNP concentration and inoculum size. Microcosm studies performed with varying concentrations (1.4-210 ppm) of PNP-spiked soils showed that strain RKJ100 could effectively degrade PNP over the range 1.4-140 ppm. A cell density of 2x10(8) colony forming units/g soil was found to be suitable for PNP degradation over a temperature range of 20-40 degrees C and at a slightly alkaline pH (7.5). Our results indicate that strain RKJ100 has potential for use in in situ bioremediation of PNP-contaminated sites. This is a model study that could be used for decontamination of sites contaminated also with other compounds.

Phytoremediation of toxic aromatic pollutants from soil.

The enormous growth of industrialization, and the use of numerous aromatic compounds in dyestuffs, explosives, pesticides and pharmaceuticals has resulted in serious environmental pollution and has attracted considerable attention continuously over the last two decades. Many aromatic hydrocarbons, nitroaromatic compounds, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, diauxins and their derivatives are highly toxic, mutagenic and/or carcinogenic to natural microflora as well as to higher systems including humans. The increasing costs and limited efficiency of traditional physicochemical treatments of soil have spurred the development of new remediation technologies. Phytoremediation is emerging as an efficient treatment technology that uses plants to bioremediate pollutants from soil environments. Various modern tools and analytical devices have provided insight into the selection and optimization of remediation processes by various plant species. Sites heavily polluted with organic contaminants require hyperaccumulators, which could be developed by genetic engineering approaches. However, efficient hyperaccumulation by naturally occurring plants is also feasible and can be made practical by improving their nutritional and environmental requirements. Thus, phytoremediation of organics appears a very promising technology for the removal of contaminants from polluted soil. In this review, certain aspects of plant metabolism associated with phytoremediation of organic contaminants and their relevant phytoremediation efforts are discussed.

Phytoremediation: an overview of metallic ion decontamination from soil.

In recent years, phytoremediation has emerged as a promising ecoremediation technology, particularly for soil and water cleanup of large volumes of contaminated sites. The exploitation of plants to remediate soils contaminated with trace elements could provide a cheap and sustainable technology for bioremediation. Many modern tools and analytical devices have provided insight into the selection and optimization of the remediation process by plant species. This review describes certain factors for the phytoremediation of metal ion decontamination and various aspects of plant metabolism during metallic decontamination. Metal-hyperaccumulating plants, desirable for heavily polluted environments, can be developed by the introduction of novel traits into high biomass plants in a transgenic approach, which is a promising strategy for the development of effective phytoremediation technology. The genetic manipulation of a phytoremediator plant needs a number of optimization processes, including mobilization of trace elements/metal ions, their uptake into the root, stem and other viable parts of the plant and their detoxification and allocation within the plant. This upcoming science is expanding as technology continues to offer new, low-cost remediation options.

Optimisation of fermentation conditions for gluconic acid production by a mutant of Aspergillus niger.

Aspergillus niger ORS-4, isolated from the sugarcane industry waste materials was found to produce notable level of gluconic acid. From this strain, a mutant Aspergillus niger ORS-4.410 having remarkable increase in gluconic acid production was isolated and compared for fermentation properties. Among the various substrates used, glucose resulted into maximum production of gluconic acid (78.04 g/L). 12% concentration led to maximum production. Effect of spore age and inoculum level on fermentation indicated an inoculum level of 2% of the 4-7 days old spores were best suited for gluconic acid production. Maximum gluconate production could be achieved after 10-12 days of the fermentation at 30 degrees C and at a pH of 5.5. Kinetic analysis of production indicated that growth of the mutant was favoured during initial stages of the fermentation (4-8 days) and production increased during the subsequent 8-12 days of the fermentation. CaCO3 and varying concentrations of different nutrients affected the production of gluconic acid. Analysis of variance for the factors evaluated the significant difference in the production levels.

Gluconic acid production by Aspergillus niger mutant ORS-4.410 in submerged and solid state surface fermentation.

Aspergillus niger ORS-4.410, a mutant of Aspergillus niger ORS-4 was produced by repeated irradiation with UV rays. Treatments with chemical mutagnes also resulted into mutant strains. The mutants differed from the parent strain morphologically and in gluconic acid production. The relationship between UV treatment dosage, conidial survival and frequency of mutation showed the maximum frequency of positive mutants (25%) was obtained along with a conidial survival of 59% after second stage of UV irradiation. Comparison of gluconic acid production of the parent and mutant ORS-4.410 strain showed a significant increase in gluconic acid production that was 87% higher than the wild type strain. ORS-4.410 strain when transferred every 15 days and monitored for gluconic acid levels for a total period of ten months appeared stable. Mutant ORS-4.410 at 12% substrate concentration resulted into significantly higher i.e. 85-87 and 94-97% yields of gluconic acid under submerged and solid state surface conditions respectively. Further increase in substrate concentration appeared inhibitory. Maximum yield of gluconic acid was obtained after 6 days under submerged condition and decreased on further cultivation. Solid state surface culture condition on the other hand resulted into higher yield after 12 days of cultivation and similar levels of yields continued thereafter.

2-(2,3-dimethylchromon-6-yl) propanoic acid (OVS-103): a potent anti-inflammatory agent.

The compound OVS-103 showed dose-dependent anti-inflammatory and anti-arthritic effects in different acute and chronic test models in rats and mice. It produced inhibition of the exudate volume and the migration of leucocytes in the carrageenan induced pleurisy test in rats. OVS-103 showed poor inhibitory effect on granuloma formation induced by cotton pellet and had no anti-pyretic and analgesic property. ALD50 in both rats and mice was more than 2000 mg/kg, p.o. and 1500 mg/kg, i.p.

Liquid-liquid extraction and reversed phase chromatographic behaviour of some 3d metal ions using bis(2,4,4-trimethylpentyl)dithiophosphinic acid (Cyanex 301).

Studies have been carried out on the extraction behavior of some metal ions of the first transition series using bis(2,4,4-trimethylpentyl)dithiophosphinic acid (Cyanex 301) from mineral acid media. The effect of various parameters influencing the extraction such as the nature of the diluent, concentration of the acid and the extractant on the distribution has been investigated. Based on the distribution data some binary separations have been proposed. A flow sheet of a scheme is given for the recovery of manganese free cobalt from a spent catalyst used in the manufacture of poly(ethyleneterepthalate).

Study on the synergistic extraction of cobalt(II) with lower fatty acids in the presence of heterocyclic amines and some metal ion separations.

The synergistic extraction of cobalt(II) with a chloroform solution of propionic, butyric or valeric acid in the presence of beta-picoline, pyridine or quinoline has been investigated. The effect of different variables, such as pH of the aqueous phase, and concentration of metal ion, acid and amine, is reported. On the basis of slope analysis the species extracted were generally found to be CoA(2).2HA.2B where HA is the acid and B the base, but CoA(2).HA.2B.H(2)O for the butyric acid-quinoline system. The extraction constants were used to assess the relative effectiveness of the amines as synergists. From the extraction data, methods for separation of Co(II) from Mn(II), Cr(III), Fe(III), Zn(II), Cd(II) and Hg(II), with fairly high separation factors, have been worked out.