A chitinolytic actinomycete Streptomyces vinaceusdrappus S5MW2 was isolated from water sample of Chilika lake, India and identified using 16S rRNA gene sequencing. It showed in vitro antifungal activity against the sclerotia producing pathogen Rhizoctonia solani in a dual culture assay and by chitinase enzyme production in a chitin supplemented minimal broth. Moreover, isolate S5MW2 was further characterized for biocontrol (BC) and plant growth promoting features in a greenhouse experiment with or without colloidal chitin (CC). Results of greenhouse experiment showed that CC supplementation with S5MW2 showed a significant growth of tomato plants and superior disease reduction as compared to untreated control and without CC treated plants. Moreover, higher accumulation of chitinase also recovered in the CC supplemented plants. Significant effect of CC also concurred with the Analysis of Variance of greenhouse parameters. These results show that the a marine antagonist S5MW2 has BC efficiency against R. solani and chitinase enzyme played important role in plant resistance.

Insects, like other organisms, are susceptible to a variety of diseases caused by bacteria, viruses, fungi and protozoans, and these pathogens are exploited for biological control of insect pests through introductory or inundative applications. Microbial pathogens of insects are intensively investigated to develop environmental friendly pest management strategies in agriculture and forestry. In this paper, the scope for utilization of insect pathogens in pest management in the world and India is reviewed. The most successfully utilized insect pathogen is the bacterium, Bacillus thuringiensis (Bt) which is used extensively for management of certain lepidopteran pests. In India, mostly imported products of Bt kurstaki have been used, which are expensive and there is an urgent need to develop aggressive indigenous Bt strains against various pests. Baculoviruses comprising nuclear polyhedrosis virus (NPV) and granulosis virus (GV) have been successfully used as insect pathogens because of their high virulence and specificity. NPV and GV formulations are used for lepidopteran pests like Helicoverpa armigera (HaNPV) and Spodoptera litura (SlNPV) in India, besides Anticarsia gemmatalis NPV in Brazil, Lymanttria disper NPV, Orgyia pseudotsugata NPV in USA and GV of Pieris rapae in China. Lack of easy mass multiplication methods for the commercial production of baculoviruses calls for R&D to develop production in insect tissue cultures. Entomopathogenic fungi like Beauveria bassiana, B. brongniartii, Metarhizium anisopliae, M. anisopliae var. acridium, Lecanicillium spp., Hirsutella thompsonii, Nomuraea rileyi and Isaria fumosorosea are gaining importance in the crop pest control in recent years due to the simpler, easier and cheaper mass production techniques. Environmental humidity and temperature play an important role in the infection and sporulation of these fungi and as such they are highly suitable during cool and humid cropping seasons. Successful uses include M. anisopliae var. acridium for locust control in Africa, Australia and China, M. anisopliae in sugarcane spittle bug management in Brazil and pine moth (Dendrolimus spp.) control in China using B. bassiana. Since talc -based formulations of these fungi have limited shelf life of 3-4 months, alternative formulations with longer shelf life (12-18 months) have to be developed besides suitable oil based formulations for dry land agriculture. There is a scope to utilize the biodiversity of Entomophthorale group of fungi like Entomophthora, Zoophthora, Neozygites etc., which have potential for management of aphids, thrips and lepidopteran pests.

Metarhizium majus and Metarhizium robertsii show enhanced activity against the coleopteran pests Holotricha serrata and Oryctes rhinoceros (Article chronicle: Received: 24.08.2017; Revised: 28.09.2017; Accepted: 30.09.2017) ABSTRACT: Studies were conducted to systematically isolate Metarhizium isolates from the insect cadavers and soils of South India.to identify the isolates at species level. Eight Metarhizium -M. robertsii J.F. Bisch., Rehner & Humber sp. nov. (ArMz3R, ArMz3S and ArMz6W), one isolate of M. majus (J.R. Johnst.) J.F. Bisch., Rehner & Humber (VjMz1W) and four isolates of M. anisopliae (WnMz1S, NlMz2S, BgMz2S and DhMz4R). Topical conidial suspensions (TCS) and powder based formulations (PBF) of the eight indigenous isolates of Metarhizium spp. that were isolated from insect cadavers and soils of South India were tested against coleopteran pests Holotricha serrata L. and Oryctes rhinoceros L. that cause serious damage to sugarcane and palm trees respectively. Against H. serrata TCS of M. robertsii (ArMz6W) 50 of 6.893×10 5 cfu/ml and caused 100% mortality against the 3 rd instar larvae in 5 days; PBF elicited an LC 50 of 7.502×10 5 cfu/ml with 96% mortality in 10 days. Against O. rhinoceros TCS (LC 50 of 9.75×10 5 cfu/ml) of M. majus (VjMz1W) caused 90% mortality in 7 days and the PBF (LC 50 of 9.57×10 5 cfu/ml) caused 86% mortality in 14 days.M. robertsii H. serrata and against O. rhinoceros M. majus

Pseudomonas putida (NBAII-RPF9) was identified as an abiotic stress tolerant bacterium capable of growing at 45 °C as well as in 1 M NaCl. The proteins expressed by this bacterium when subjected to these two stresses were analyzed by 2D gel and MALDI-TOF/MS. Two parameters viz., heat/saline shock (20 min at 45 °C/1 M solid NaCl added at mid log phase and incubated for 1 h) and heat/saline tolerance (24 h growth at 45 °C/in 1 M NaCl) were studied. Under heat shock 13 upregulated proteins and 1 downregulated protein were identified and under tolerance 6 upregulated proteins were identified. GroES and GroEL proteins were expressed under both tolerance and shock. Under saline shock 11 upregulated proteins were identified whereas under saline tolerance 6 upregulated proteins were identified and all these proteins had pI between 3 and 10 with molecular weights ranging from 14.3 to 97 kDa. Aspartate carbamoyltransferase was common under both the saline conditions studied. The analysis revealed involvement of heat stress responsive molecular chaperones and membrane proteins during heat stress. During salt stress, proteins involved in metabolic processes were found to be upregulated to favor growth and adaptation of the bacterium. Heat shock chaperones viz., DnaK and DnaJ were expressed under both saline and heat stress. This is the first report of protein profile obtained from a single bacterium under saline and heat stress and the studies reveal the complex mechanisms adapted by the organism to survive under high temperature or saline conditions.

The Oriental armyworm, Mythimna separata Walker (Lepidoptera: Noctuidae) is a major pest of cereal crops, and its outbreaks result in complete crop loss. In this study, we tested the pathogenicity and reproductive potential of indigenous entomopathogenic nematodes (EPNs), Heterorhabditis indica Poinar, Karunakar, & David NBAIIH38, Steinernema abbasi Elawad NBAIISa01, S. carpocapsae Weiser NBAIISc05 and S. siamkayai Stock, Somsook and Reid NBAIRS92 against larval and pupal stages of M. separata under laboratory conditions. Steinernema carpocapsae caused significantly greater mortality in second‐ and fourth‐instar larval stages than other EPNs species. Steinernema carpocapsae caused greatest mortality 100% in larval stages and 75% in pupal stages. Significant differences were observed in the lethal concentration values (LC50 and LC90) of EPNs species against different stages of M. separata. Differences in penetration and multiplication in the fourth‐instar larval stages of M. separata were observed amongst the EPNs species. However, further studies are needed to reveal the field performance of EPN isolates tested to be included in the IPM programme of M. separata.