Immobilized biocatalyst such as enzymes, microbial cells and cellular organelles, seem to be useful for continuous monitoring of the metabolites because of their high sensitivity and substrate specificity. The approach by confining enzymes in a defined space is extremely useful for enzyme reutilization and particularly favorable for applied bioprocess and it is apparent that Escherichia coli remains widely accepted as top choice among the bacterial cells. Free and immobilized Escherichia coli were exposed to methomyl of concentrations ranging from 10-7 M to 10-3 M for a period of 96 hrs and protease activity was evaluated at regular intervals of 24, 48, 72 and 96 hrs. The results indicated a close correlation between the toxic effects in free and immobilized cells. The protease activity increased significantly with an increase in the dose and duration of exposure to methomyl in both free and immobilized cells, however, in comparison with its free counterpart the protease activity was less in immobilized Escherichia coli cells revealing that immobilized system shows selective proteolysis and is less sensitive to the toxicant.

Pseudomonas fluorescens is one of the major fungal biocontrol agents found in the soil and the rhizosphere of various crop systems. Ten isolates of P. fluorescens were isolated from rhizosphere soil samples collected from various tomato-growing fields and evaluated for their efficacy in increasing seed quality variables of tomato and in inhibiting the mycelial growth of Fusarium oxysporum. Pseudomonas isolate 2 produced effective results and was selected and mass multiplied. Talc and sodium alginate formulations of mass multiplied using different agents were prepared and evaluated for their effects against fusarium wilt under greenhouse conditions. Fresh cultures of Pf2 isolate was found to increase seedling emergence and reduce fusarium wilt disease incidence when compared to the control and the formulations.

Preliminary screening of the mine water sample from bauxite ore deposits in Jamnagar, India showed the presence of heterotrophic bacteria B.polymyxa. Growth conditions for the bacteria to bring about maximum beneficiation were standardized by using the enriched Bromfield medium. B.polymyxa brought significant changes in the surface modifications of the mineral magnetite. The interaction resulted in surface chemical changes both on the cell and on the mineral surface by studying their electrophoretic mobility using Zeta meter 3.0. Dissolution studies in the presence of microorganisms establish the foundation in which these processes could be used for the utility of beneficiation in the efficient separation of the impurities from the ore, thus confirmed that B.polymyxa has greater affinity towards magnetite and could be efficiently used to remove iron from magnetite. Experiments with respect to the bauxite ore was initiated after confirming the above result. Iron removal from bauxite ore by B. polymyxa has been demonstrated under 2% sucrose concentrations brought about 12.5% removals in four days and under similar conditions the control in absence of B. polymyxa only 6% iron removal was seen. Thus, B. polymyxa plays a significant role in biobenficiation of bauxite mineral. These observations clearly indicate that a direct mechanism through bacterial attachment to the ore and an indirect mechanism through leaching with metabolites are involved in the biobeneficiation process.

Background: Amidst continued calls for more research investigating the relationship between the use of antibacterial wash products and antibiotic and antibacterial resistance in human-source bacteria, this study aimed to describe susceptibilities in staphylococcal skin isolates from community users of antibacterial wash products, compared to isolates from non-users. Methods: Qualified and randomly selected participants (n=210) comprised three equal groups: 1) those that frequently used wash products containing triclosan; 2) those that frequently used products containing triclocarban; 3) control group that used no antibacterial wash products. A forearm swab sample was collected from each participant and processed for coagulasenegative Staphylococcus species and S. aureus (SA). Standard antibiotic and antibacterial minimal inhibitory concentration (MIC) testing was performed on all isolates (n=317). Results: There was no statistically significant difference in antibiotic resistance in Staphylococcus isolates from regular antibacterial wash product users compared with non-users. None of the isolates were resistant to vancomycin, and the rate of methicillin resistant S. aureus (MRSA) detected was appreciably less than that reported in the literature for both hospital inpatient and outpatient isolates of SA. There was also a definitive lack of antibiotic/antibacterial cross-resistance. Conclusion: An extensive community study of resident skin Staphylococcus showed no increased antibiotic resistance in participant groups regularly using wash products containing triclocarban (TCC) or triclosan (TCS), as compared with participants using wash products containing no TCC or TCS. This adds to and confirms previous yet limited community data showing lack of evidence that the use of antibacterial wash products facilitates antibiotic resistance and antibiotic/antibacterial cross-resistance.

A cellobiohydrolase gene cbh1 was cloned from a cellulolytic fungus, Penicillum funiculosum NCL1. Nucleotide sequencing of cbh1 gene revealed that this gene was 1590 bp length encoding a putative protein consisting of 529 amino acids. The deduced amino acid sequence showed that the predicted molecular mass of the CBHI was 54.9 kDa, and showed significant homology to glycoside hydrolase family 7 cellobiohydrolases. The cbh1 gene was cloned using pET30b and expressed in E. coli BL21 (DE3). The expression analysis of the recombinant E. coli BL21 (pETC7) revealed the production of cbh1 transcript; however, functional cellobiohydrolase could not be detected. Therefore, the cbh1 gene was sub-cloned into GST tagged expression vector pGEX4t-3. The GST tagged cellobiohydrolase was purified to homogeneity using affinity chromatography. The recombinant enzyme exhibited optimum catalytic activity at pH 5.0 and 50 °C respectively. It was thermostable at 50 °C and retained 70% of its original activity after 30 min at 60 °C.

L-asparaginase (L-asparagine amido hydrolase, E.C.3.5.1.1) is an extra cellular enzyme that has received considerable attention since it is used as an anticancer agent. In the present study, the fungal isolates from rhizosphere soils were screened for the L-asparaginase production by using modified Czapek Dox agar containing L-asparagine and phenol red as indicator. The strain isolated from rhizosphere soil of Ipomoea muricata showed the maximum zone diameter of 1.05 cm. The 16s rDNA sequence analysis indicated that the strain was most closely related to Fusarium equiseti. Various physical and chemical parameters were optimized under solid state fermentation (SSF) for L-asparaginase production. Further, it was observed that maximum activity of 3.26 IU was achieved by employing soya bean meal as substrate, with incubation period of 48 hrs and incubation temperature at 45oC at pH 7 with di potassium hydrogen phosphate and manganese as the best phosphate and metal ion source respectively.

Sheath blight (ShB) of rice caused by Rhizoctonia solani is an economically important disease, causing significant yield losses. In this study, the growth promoting activities of commercial formulation of a bioagent, Bacillus subtilis MBI 600 (Integral ®) and its compatibility with rice fungicides were evaluated. Integral was evaluated for growth promotion in rice on four cultivars (Cocodrie, Catahoula, Neptune, and Trenasse) under in vitro conditions. Treated rice seeds were incubated for 7 days, and the shoot and root lengths were measured. Rice cv. Cocodrie seeds were treated with strain MBI 600 at various concentrations and seeded in pots containing field soil in GH in a randomized complete block design. Germination and seedling lengths were measured at 7 and 15 days after sowing (DAS). The strain MBI 600 was found to produce siderophores. Seed treatment with Integral significantly increased shoot and root lengths at all concentrations in cvs. Cocodrie, Catahoula, and Trenasse under in vitro conditions. The shoot lengths ranged from 39 to 42 mm at a concentration of 2.20 x 10⁹ cfu/ml in all CV’s. At 2.20 x 10⁹ cfu/ml, the root lengths ranged from 47 to 69 mm. The shoot and root lengths of control seedlings were each up to 20 mm. Seed treatment with 2.20 x 108 and 2.20 x 10⁹ cfu/ml significantly increased seedling emergence (81 to 89%) compared to 2.20 x 10⁶ and 2.20 x 10⁷ cfu/ml, and control (61%) under GH conditions. Similarly, seed treatment with 2.20 x 10⁹ cfu/ml of MBI 600 resulted in the highest shoot and root lengths (335 and 166 mm respectively). Integral has good tolerance to hexaconazole, propiconazole, and validamycin; moderate tolerance to tricyclazole; and poor tolerance to benomyl and mancozeb at 1000 ppm. Integral showed compatibility to carbendazim and azoxystrobin up to 400 ppm. Overall, our results suggest that Integral produces siderophores, promoted rice seedling emergence and growth, and is compatible with rice fungicides.