Quantification of polyphenols during retting and characterization of bacteria from the Kadinamkulam Backwaters, Kerala.

The retting environment which provides a competitive niche for specialized microbes is speculated to harbour a variety of microbes with high biodegradation potential. In this context, an effort has been made to isolate and identify bacterial species having high tolerance to phenol In vitro. Maximum polyphenol (1.897 mg l-1 ) as observed during the initial period of retting, which decreased as retting proceeded. Based on biochemical characterization, the isolated bacterial strains were identified as Micrococcus sp., Moraxella sp. strain MP1, Moraxella sp. strain MP2 and Moraxella sp. strain MP3, Pseudomonas sp. strain PP1 and Pseudomonas sp. strain PP2, Amphibacillus sp., Brucella sp. strain BP1 and Brucella sp. strain BP2, Aquaspirillum sp., Escherichia coli strain EP1 and Escherichia coli strain EP2, Campylobacter sp., Aeromonas sp., Neisseria sp., Vibrio sp., Erwinia sp. and Mesophilobacter sp. These strains were found to tolerate maximum concentration of phenol viz. 200 to 1000 mg l-1. Plasmid analysis of phenol resistant bacterial isolates showed that almost all the cultures had at least one plasmid of size >1Kb. Studies on the protein profile of isolated bacterial cultures showed the presence of proteins with molecular sizes ranging from 10 to 85 KDa with exception of Mesophilobacter and Neisseria having still high molecular weight protein (95 KDa). Bacterial strains isolated from coir-ret-liquor showed tolerance to high phenol concentration.

Macroinvertebrate diversity of Veli and Kadinamkulam lakes, South Kerala, India.

The diversity and distribution pattern of benthic macroinvertebrates in two backwaters viz., Veli and Kadinamkulam of Kerala were assessed using diversity indices. The samples were collected once in three months for a period of two years from six sampling sites (K1, K2, K3, V1, V2 and V3) and community variations were analyzed. Overall, 24 families were identified represented by mollusca, annelida and arthropoda (crustaceans and insects). Among this, dominant taxon was Mytilidae of molluscan family and site-wise dominance was maximum in sites V1 and V2. Richness and abundance were highest in site V2 and lowest in site K2. Diversity index ranged from 0.27 (K2) to 2.33 (V1). The diversity and distribution patterns of certain species were clearly related to water quality as evident from the present study.

In vitro study on the influence of methyl parathion on soil bacterial activity.

A study was conducted to find out the effect of different concentrations of Methyl parathion, an organophosphorus pesticide on soil bacterial population, soil respiratory activity and dehydrogenase activity, under laboratory conditions for a definite time period. The higher concentration (100 ppm) of Methyl parathion application, considerably reduced bacterial count, CO2 evolution and enzyme activity in soil but the microbial activities seemed to recover several weeks following pesticide application.