Potential of Brachiaria mutica (Para grass) for bioethanol production from Loktak Lake.

The aim of present study was to evaluate feasibility of using the Para grass as feedstock for production of bioethanol. Process involved the pretreatment with dilute acid or alkali and followed by enzymatic saccharification with commercial cellulase. Maximum sugar release of 696mg/g was obtained from 10% biomass loading and 0.5% w/v of alkali whereas in the case of acid pretreatment maximum sugar of 660mg/g was obtained from 20% biomass loading and 2% w/v acid loading. Results showed that Para grass utilization as a biorefinery feedstock can be a potential strategy to address the sustainable utilization of this invasive grass thereby keeping its population in check in the Loktak Lake.

Characterization of the bioactive metabolites from a plant growth-promoting rhizobacteria and their exploitation as antimicrobial and plant growth-promoting agents.

A plant growth-promoting bacterial strain, PM 105, isolated from a tea plantation soil from the North Eastern region of India was identified as Pseudomonas aeruginosa through classical and 16S ribosomal DNA (rDNA) gene sequencing. Further studies with this strain confirmed broad spectrum antifungal activity against ten human and plant pathogenic fungal pathogens viz. Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger, Aspergillus tubingensis, Candida albicans, Colletotrichum gloeosporioides, Fusarium oxysporum, Pencillium expansum, Rhizoctonia solani, Trichophyton rubrum besides growth-promoting property in cowpea (Vigna unguiculata) and pigeon pea (Cajanus cajan). However, no antibacterial property was exhibited by this strain against the four test bacterial pathogens tested in agar overlay method. The crude bioactive metabolites produced by this strain were isolated with three different solvents that exhibited significant antimicrobial and plant growth-promoting activity. Chloroform extract recorded significant antimicrobial and plant growth-promoting activity. Three major compounds viz. 1-hydroxyphenazine, pyocyanin, and phenazine-1-carboxamide were purified and characterized from crude extracts of this strain by various spectral data. The purified compounds recorded prominent antimicrobial activity but failed to establish the plant growth promotion activity in test crop plants under gnotobiotic conditions. Pyocyanin recorded significant antimicrobial activity, and best activity was recorded against T. rubrum (29 mm), followed by P. expansum (28 mm). These results suggest the use of PM 105 as plant growth-promoting agent in crop plants after successful field trials.