Unveiling the optimal parameters for cellulolytic characteristics of Talaromyces verruculosus SGMNPf3 and its secretory enzymes.

AIMS: Elucidation of different physico-chemical parameters and the secretory enzymes released by Talaromyces verruculosus SGMNPf3 during cellulosic biomass degradation. METHODS AND RESULTS: We determined the optimal pH, temperature and time course parameters for the efficient degradation of different natural and commercial cellulosic substrates by T. verruculosus SGMNPf3, previously isolated from a forest soil. The optimal growth of the fungus and production of its cellulases were obtained when the culture condition was maintained at pH 3·3 and temperature 30°C. Activity of the crude cellulases was maximum at 60°C. Activity of cellulase enzymes produced on natural cellulose substrates was higher than that on commercial cellulose substrates. A continuous increase in cellulase activity at different time points indicated no apparent end product inhibition. This might be attributed to the high individual cellulases, notably ß-glucosidase (316·1 µmol g(-1) ) production. Zymogram of extracellular crude proteins showed two dominant extracellular protein bands of molecular weight 72·3 and 61·4 kDa, indicating their cellulolytic nature. MALDI-TOF and LC-MS/MS analysis of the 2DE spots also identified several enzymes including ß-glucosidase involved in the process of cellulose degradation. CONCLUSIONS: Based on its optimal parameters for cellulolytic activities, we suggest that the fungus is acido-mesophilic. There was apparently no end-product inhibition of the cellulase activity and this is attributed to the ability of the fungus to produce sufficient ß-glucosidase. The dominant proteins secreted by the fungus were confirmed to be cellulases. SIGNIFICANCE AND IMPACT OF THE STUDY: The high individual cellulase activities, better cellulase production on natural substrates and apparent absence of end-product inhibition are characteristics of T. verruculosus SGMNPf3 for use in harvesting naturally endowed energy in cellulosic biomass.

Assessment of genetic diversity of landraces of Dendrocalamus hamiltonii using AFLP markers and association with biochemical traits.

Fermented bamboo shoots are popular traditional food items of various ethnic groups of the northeastern India, especially in Manipur State. Dendrocalamus hamiltonii is an economically important bamboo species used to produce fermented bamboo shoots. We studied genetic variability of this bamboo species in Chandel and Imphal-East (commercial production districts), using AFLP molecular markers. Each of the selected primers detected polymorphisms and 1614 (95.8%) were found to be polymorphic. Cluster analysis based on Dice similarity coefficients using UPGMA differentiated the populations into two major groups. Principal coordinate analysis based on the AFLP data clearly separated the populations according to their genetic diversity and antioxidant activity. Four primers were tested through multiple regression analysis to identify marker-trait association between AFLP data and biochemical attributes, i.e., antioxidant activity and total cyanide content. The 273 bp generated by EcoRI-AAG(Joe)/MseI-CTC showed high positive correlation with antioxidant activity (r = 0.729, P < 0.01). The 396 bp generated by EcoRI-AAC(Ned)/MseI-CTG were negatively correlated with cyanide content (r = -0.694, P < 0.01). Thus, we found association of DNA markers with antioxidant activities and total cyanide content. These results could be of use for the identification of superior genotypes with desirable traits.

Carbon dots derived from water hyacinth and their application as a sensor for pretilachlor.

Recently,carbon-based nanomaterials have been attracted much interest among the scientific community due to its extraordinary properties and applications. Mostly the fluorescent carbon nanomaterials are prepared from commercially available precursors. In this work, develop a new strategy for producing carbon nanoparticles (carbon dots) using phosphoric acid as an activating agent from water hyacinth present in Assam, India. These carbon nanoparticles show green fluorescence under UV light, and the sizes are found below 10 nm. These carbon dots are applied as a fluorescence sensor for detecting the herbicide (pretilachlor). The developed PL sensor is exclusively selective and sensitive for detection of this herbicide, and the limit of detection is found to be 2.9 µM.This sensor is also tested for real samples like soil contaminated with pretilachlor.

Molecular identification of dominant microflora associated with 'Hawaijar' - a traditional fermented soybean (Glycine max (L.)) food of Manipur, India.

The dominant microorganisms in 'Hawaijar', a traditional non-salted fermented soybean (Glycine max (L.)) food of Manipur, India, were isolated and identified by molecular techniques. Bacillus spp. were the predominant microorganisms in 'Hawaijar'. A total of 274 isolates were obtained from forty-one 'Hawaijar' samples collected from household preparations and markets of valley districts of Manipur. Phenotypic grouping followed by Amplified Ribosomal DNA Restriction Digestion Analysis (ARDRA), PCR amplification of 16S-23S rDNA region, RFLP by Hae III and Hind III double digest (by comparing MTCC type strains) and sequencing of 9-1514 region of 16S rDNA resulted in three major phylogenic groups. Bacillus subtilis group comprising B. subtilis and B. licheniformis representing 112 isolates, B. cereus group representing of 128 isolates and Staphylococcus spp. group comprising S. aureus and S. sciuri representing 23 isolates. A few bacterial isolates belongs to Alkaligenes spp. and Providencia rettgeri were also found. Genetic diversity of B. subtilis phylogenic group was investigated by RAPD-PCR. Eighty-two strains of B. subtilis phylogenic group were identified using RAPD-PCR using OPA-18 and OPA-20 primers. These strains will be investigated for potential starter culture selection.

Anti-diabetic molecules from Cycas pectinata Griff. traditionally used by the Maiba-Maibi.

Bioactivity guided chemical investigation on active anti-diabetic constituents of the fruits of Cycas pectinata Griff. (FCP) characterized EAFr-5 as the most potent sub fraction which significantly reduced the blood glucose level to normal in STZ induced diabetic rats. It was shown to contain the biflavonoids amentoflavone (1) and 2,3-dihydroamentoflavone (2) which exhibited significantly high inhibitory potency against α-glucosidase (IC50 8.09 ± 0.023 and 9.77 ± 0.032 µM, respectively) and α-amylase (IC50 73.6 ± 0.48 and 39.69 ± 0.39 µM, respectively). This is the first report of bioactivity guided isolation of anti-diabetic constituents from the traditionally used fruits of Cycas pectinata Griff.

Molecular and functional characteristics, growth promoting effect and persistence of selected parent isolates and streptomycin resistant derivatives of rice rhizobacteria.

Molecular and functional characteristics of seven azospirilla and five phosphorus solubilizing bacteria (PSB) isolates of rice rhizosphere, growth promotion ability of two efficient strains, Azospirillum amazonense A10 (MTCC4716) and Bacillus megaterium P5 (MTCC4714) and their persistence based on streptomycin resistant derivatives (SRD), were determined. SDS-PAGE and isozyme banding patterns of the isolates were used to arbitrarily group the azospirilla into 4 and PSB into 3 clusters and as markers to ascertain their identity. The azospirilla produced 2.0 to 10.5 ppm of IAA like substances and showed nitrogenase activity of 0.02 to 3.55 nmole C2H4/hr/ml of pure culture. PSB isolates produced 7.8 to 15.0 ppm IAA like substances and 20 to 128 ppm soluble P. Induction of resistance to streptomycin resulted in changes of these properties. Co-inoculation of rice with SRD A10 and SRD P5 and their parental strains in separate treatments enhanced grain yield over control by 31 and 12.4%, respectively. Nitrogenase activity of rice roots under SRD co-inoculated treatment was higher (4.16 nmole C2H4/hr/hill) than that-under parental strains co-inoculated treatment (3.76 nmole C2H4/hr/hill). SDS-PAGE profile and population count of the strains confirmed their establishment in rice rhizosphere and persistence over a year after inoculation.

Screening of Rhizobacteria for Their Plant Growth Promotion Ability and Antagonism Against Damping off and Root Rot Diseases of Broad Bean (Vicia faba L.).

Development of microbial inoculants from rhizobacterial isolates with potential for plant growth promotion and root disease suppression require rigorous screening. Fifty-four (54) fluorescent pseudomonads, out of a large collection of rhizobacteria from broad bean fields of 20 different locations within Imphal valley of Manipur, were initially screened for antifungal activity against Macrophomina phaseolina and Rhizoctonia solani, of diseased roots of broad bean and also three other reference fungal pathogens of plant roots. Fifteen fluorescent pseudomonas isolates produced inhibition zone (8-29 mm) of the fungal growth in dual plate assay and IAA like substances (24.1-66.7 µg/ml) and soluble P (12.7-56.80 µg/ml) in broth culture. Among the isolates, RFP 36 caused a marked increase in seed germination, seedling biomass and control of the root borne pathogens of broad bean. PCR-RAPD analysis of these isolates along with five MTCC reference fluorescent pseudomonas strains indicated that the RFP-36 belonged to a distinct cluster and the PCR of its genomic DNA with antibiotic specific primers Phenazine-1-carboxylic acid and 2, 4-diacetyl phloroglucinol suggested possible occurrence of gene for the potent antibiotics. Overall, the result of the study indicated the potential of the isolate RFP 36 as a microbial inoculant with multiple functions for broad bean.