Comparative profiles of alpha-amylase production in conventional tray reactor and GROWTEK bioreactor.

GROWTEK bioreactor was used as modified solid-state fermentor to circumvent many of the problems associated with the conventional tray reactors for solid-state fermentation (SSF). Aspergillus oryzae IFO-30103 produced very high levels of alpha-amylase by modified solid-state fermentation (mSSF) compared to SSF carried out in enamel coated metallic trays utilizing wheat bran as substrate. High alpha-amylase yield of 15,833 U g(-1) dry solid in mSSF were obtained when the fungus were cultivated at an initial pH of 6.0 at 32 degrees C for 54 h whereas alpha-amylase production in SSF reached its maxima (12,899 U g(-1) dry solid ) at 30 degrees C after 66 h of incubation. With the supplementation of 1% NaNO(3), the maximum activity obtained was 19,665 U g(-1) dry solid (24% higher than control) in mSSF, whereas, in SSF maximum activity was 15,480 U g(-1) dry solid in presence of 0.1% Triton X-100 (20% higher than the control).

Optimization of some additives to improve protease production under SSF.

In a locally isolated Rhizopus oryzae strain highest-production of protease (388.54/g wheat bran) was observed in presence of Tween-80 and dioctyl sodium sulfosuccinate individually at 40mg/g wheat bran concentration. Under solid state fermentation biotin (0.0025mg/g wheat bran); Ca2+ (0.05mg/g wheat bran) and 1-Naphthyl acetic acid (0.01mg/g wheat bran) also showed some inducing effect on the synthesis of the enzyme protease by solid state fermentation.

Optimization of n variable biological experiments by evolutionary operation-factorial design technique.

Since the traditional approach to optimization of biological systems based on the single variable search technique is incapable of detecting the true optimum when a number of chemicals are used together as inducers, the Evolutionary Operation (EVOP)-factorial design technique was applied successfully to optimize the concentrations of vitamin (biotin), metal ion (CaCl(2)) and plant hormone (NAA) for maximizing enzyme (protease) production by Rhizopus oryzae (RO IIT RB-13, NRRL-21498) in solid state fermentation. Addition of inducers to an optimal level (biotin-2.5 ppm, CaCl(2)-20 ppm and NAA-12.5 ppm) resulted in a approximately 1.9-fold increase in protease production.

HLA-DR polymorphism modulates the cytokine profile of Mycobacterium leprae HSP-reactive CD4+ T cells.

In the present study, in vitro attempts have been made to define the cytokine profile of CD4+ T cells from polar leprosy patients and healthy individuals against Mycobacterium leprae-derived heat shock proteins (HSPs), HSP65 and HSP18, and their trypsin-digested fragments, relating to HLA-DR polymorphism. While all tryptic fragments of optimal digestion and undigested HSPs could stimulate CD4+ T cells from tuberculoid (TT) leprosy patients and healthy contacts (stimulation index, SI > 2.0), only two fragments, TDB65-2 (18 kDa) and TDB18-3 (3 kDa) triggered CD4+ T cells of anergic lepromatous (LL) leprosy patients. Both of these HSPs and their tryptic fragments showed diverse HLA-DR restriction, with DR15 providing the strongest restriction. Cytokine analysis demonstrated that HSP65 and HSP18 induced Th1-like activity in the context of all the restricting HLA-DR alleles, except DR1 and DR7 which induced a Th2 type of response against HSP65 and HSP18, respectively. These Th2 inducer epitopes on HSP65 (DR1 restricted) and HSP18 (DR7 restricted) were absent from TDB65-2 and TDB18-3 which exclusively triggered Th1 cells in both TT and LL forms of leprosy in the context of multiple DR alleles, DR15 being the major antigen-presenting allele. These studies suggest that the major histocompatibility complex phenotype of the antigen-presenting cell can modulate Th1-like versus Th2-like activity against M. leprae pathogens in leprosy and healthy individuals.

Production of some extracellular enzymes by a lignin peroxidase-producing brown rot fungus, Polyporus ostreiformis, and its comparative abilities for lignin degradation and dye decolorization.

Polyporus ostreiformis produced Mn peroxidase, acid protease, alpha-amylase, and lignin peroxidase, with maximum activities of 40, 8,300, and 4,200 U liter-1 and 50 nkat liter-1, respectively, in nitrogen-limited liquid media. The fungus removed only 18.6% lignin from rice straw in 3 weeks but effected 99% decolorization of Congo red dye in 9 days.

Evolutionary operation (EVOP) to optimize three-dimensional biological experiments.

Evolutionary operation (EVOP) is used as an efficient technique for optimization of three variable experimental parameters using two-level factorial designs with center points. For metabolic function like enzyme synthesis by microorganisms, small amounts of metal ions, surfactants, and vitamins act as inducers. The desired quantities of these chemicals are, however, species dependent and have to be found out or each microorganism. By employing the EVOP technique, the requirements of these chemicals have been optimized for the production of protease by Rhizopus oryzae (RO, IIT KGP).

Rapid mass propagation of Chrysanthemum morifolium by callus derived from stem and leaf explants.

A procedure for rapid multiplication of Chrysanthemum morifolium RAMAT cv. Birbal Sahni using leaf callus and stem (nodal/internodal) callus as well as node and apical shoots has been developed. Murashige and Skoog's medium (1962) supplemented with 2mg/1 2,4-D yielded good green calli from both leaf and stem segments within 2 weeks. About 1 cm × 1 cm callus regenerated 2-3 shoots after 3 weeks on MS solid medium supplemented with 0.1 mg/l IAA and 0.2 mg/l BAP. Each of the regenerated shoots when transferred to the same shooting medium without agar yielded about 150 new shoots, which in turn regenerated roots after another week in MS half strength or modified White's media (Rangaswamy, 1961). It has been estimated that about 10(14) plantlets could be produced in a year from one expiant following the proposed protocol.