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Chemical analysis of hexane and ethyl acetate soluble fractions obtained from the rhizobacteria Pseudomonas jessenii strain R62 and Pseudomonas synxantha strain R81 was carried out using gas chromatography-mass spectrometry and their nematicidal activity was evaluated against root-knot nematode, Meloidogyne incognita second stage juveniles (J2). Results showed that the hexane extract of both strains, together with mixed ethyl acetate extract, were found to have better nematicidal activity than their individual ethyl acetate fractions above 100 ppm. Some of the chemical compounds of these bioactive fractions were identified using gas chromatography-mass spectroscopy (GC–MS) analysis. A total of sixteen and six similar compounds were detected in hexane and ethyl acetate fractions, respectively from both bacteria. The major compounds, namely hexadecenoic acid and hexadecanoic acid may be responsible for the nematicidal activity.

Arbuscular mycorrhizal fungi are important for controlling soil-borne diseases and could be important for managements of root-knot disease. Effective co-inoculation of mycorrhiza (Rhizophagus irregularis) and root-knot nematode (Meloidogyne incognita) on plant growth, physiological and biochemical changes during root-knot nematode infection into tomato (Lycopersicon esculentum cv. PT-3) plants were studied. Experiments were conducted under controlled conditions and carried up to one month after nematode inoculation. Rhizophagus irregularis treated plants significantly enhanced plant growth and reduced nematode induced parameters. They also exhibited potent activity of phenolics and defensive enzymes i.e. peroxidase (PO), polyphenyloxidase (PPO) and superoxide dismutase (SOD) while a significant reduction was recorded in malondialdehyde (MDA) and hydrogen peroxide (H2O2) content. Both physiological and biochemical parameters were significantly improved in response to Rhizophagus irregularis. These finding indicates the importance of Rhizophagus irregularis as a potential biocontrol tool for the management of root-knot disease.

Root-knot disease poses a worldwide problem to agriculture; hence, several environmentally hazardous chemical nematicides are being used to control it. Rhizobacteria could be one of the important biocontrol agents which can replace these chemicals. This study focused on the effect of bacterial cell-free culture filtrate against Root-knot nematodes. Experiment was conducted to observe the effect of different dilutions of cell-free culture filtrate on Meloidogyne incognita under laboratory and in greenhouse conditions. In laboratory, toxicity effect of filtrate was recorded on second stage juveniles (J2), 100% mortality was recorded in all treatment above the 75% concentration. In greenhouse, all the growth and nematode induced parameters were significantly differed after culture filtrate treatment to the tomato plants. The finding indicates the capability of fluorescent Pseudomonad's culture filtrate as a powerful biocontrol tool for the management of Root-knot nematodes.

Manufacturing of protein/enzymes by biotechnological methods may contribute to develop new protein/enzyme preparations useful in various sectors of industry. Microbial enzymes released in growing medium and difficult to isolate. In this study, a rapid method has been developed for isolating extracellular proteins from cultured nutrient broth. After removing the bacterial cells from cultured broth through 0.4mm filter paper and dissolved proteins recovered by precipitation with 5% trichloroacetic acid (TCA). Sodium dodecyl sulfate - polyacrylamide gel electrophoresis (SDS-PAGE) analysis of the isolated crude enzymes from bacterial cell free culture filtrate showed the presence of different bands in the electrophoretic field.

Four species of Indian desert rodents, viz. Tatera indica, Meriones hurrianae, Rattus meltada and Golunda ellioti have been found to have basal metabolic rates (BMR) lower than the values expected from the metabolic rate-body weight relationship for mammals. The low BMR in these species is evidently not due to any large accumulation of body fats, but is probably related to niche utilization. Of the four species examined, only T. indica and M. hurrianae have any appreciable body fat, presumably for use during summer when scarcity of both food and water prevail.

Measurement of the metabolic rates of eight species of Rajasthan desert rodents and of Rattus rattus at a moderately low temperature (21 °C) during winter has revealed that: there is a significant negative correlation (P

Basal metabolic rate (BMR), evaporative water loss (EWL) within the thermoneutral zone and minimal thermal conductance (C) of the Indian desert gerbil Meriones hurrianae Jerdon, were 0·79 cm3 O2/g/h, 1·89 mg H2O/cm3 O2 and 0·110 cm3 O2/g/h/°C respectively. Below the thermoneutral zone, gerbils regulated their body temperature within the normal limits of homeotherms. The relatively high body temperature (38·7 °C) recorded within the thermoneutral zone is, presumably, the result of an adaptive mechanism for reducing evaporative water loss. The gerbil's low BMR, low conductance (67 and 92 per cent of the values predicted on body weight basis respectively) and its comparatively high body temperature are considered to be physiological means of avoiding overheating.

The responses of Meriones hurrianae deprived of food and food-cum-water were found to be similar in respect of time spent in feeding, exploration and drinking whereas water- deprived gerbils fed for a significantly (P < 0.01) shorter time. However, they explored twice (P < 0.01) as long as gerbils in the other two conditions of deprivation. These observations indicate that deprivation of water increases exploratory behaviour among M. hurrianae but food, and food-cum-water deprivation do not seem to influence it. The behaviour of M. hurrianae, when deprived of water, mostly alternated between exploration and drinking whereas feeding was the major behavioural component of the gerbils deprived of food, and food-cum-water. It appears that feeding behaviour among M. hurrianae is of a higher order than drinking behaviour since the animals depend chiefly on the available water content of the food in their natural invironment - the desert.