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A consortium of already isolated strains has been applied to degrade endosulfan. These were identified by 16S rRNA technique as Stenotrophomonas maltophilia EN-1, Pseudomonas sp. TAH and Enterobacter sp EN-2. Batch experiments were conducted to access the endosulfan degradation efficiency of consortium while using various concentrations of endosulfan (5, 25, 50, 75, 100 mg/L). Maximum degradation of about 85–90% was observed at a concentration of 100 mg/L after 96 hours of incubation while no degradation was observed in untreated ones (without consortium). Cell growth kinetic models were applied to explain the kinetic behaviors of bacterial consortium in batch study. Various kinetic parameters such as 'µmax' and 'Ks' were determined having values of 0.9 h−1 and 7.9 mg/L respectively, that depicts the faster rate of endosulfan degradation by the selected bacterial consortium. Conversely, first-order kinetics was also well fitted in the experimental data using least squares regression (R2) ranged from 0.09 to 0.95, which indicates that the endosulfan utilization was stimulated by a synergistic interaction of each bacterial strain in the consortium. [ABSTRACT FROM AUTHOR]

A bacterial strain (TA7) capable of consuming three N-methylated carbamates as sole nitrogen and carbon source was isolated and identified as "Enterobacter cloacae" on the basis of 16S rRNA, from carbamate contaminated agricultural soil by enrichment culture technique. The agar entrapment was used to immobilize the bacterial cells. Both the free as well as the immobilized cells were used to study the degradation of three carbamets viz. aldicarb, carbofuran, and carbaryl. The immobilized cells degraded all the three carbamates much faster than their free cell counterparts. The biodegradation kinetics of aldicarb, carbaryl, and carbofuran was studied using 50 ppm as initial concentration in the presence of free cells. The average values of Ks for aldicarb, carbofuran, and carbaryl were 22.6, 17.87, and 8.9 mg/L, respectively, whereas the values for µmax were calculated as 1.35, 1.3, and 1.2 mg/l/h−1. The results indicated that the bacterium has high affinity towards all the three carbamates. However, relatively higher affinity is for carbaryl, in comparison with carbofuran and aldicarb. Results indicate the potential of E. Cloacae TA7 to remediate N-methylated carbamates polluted water and soil. [ABSTRACT FROM AUTHOR]

Recognizing the potential significance of using nuclear techniques in biological control, investigations were conducted on the rearing of parasitoids of the peach fruit-fly,Bactrocera zonata(Saunders) (Diptera: Tephritidae) to lead to a greater flexibility in the use of irradiated hosts. For improving mass production of the biological control agents, the use of irradiated fruit-fly larvae at the dose of 15 Gy proved useful for enhancing the parasitism and adult emergence of the larval parasitoid,Trybliographa daci(Weld) (Hymenoptera: Eucoilidae) due to no negative repercussions on parasitoid development. Overall, parasitism by the parasitoid increased with age of the host larvae; however, significantly higher parasitism occurred on 4 d-old irradiated larvae ofB. zonatacompared to those aged 5 d. The female parasitoids preferred the irradiated larvae, and significantly higher numbers of larvae were parasitized compared with non-irradiated larvae. There was no significant difference in adult parasitoid emergence with respect to the sex of the host. A radiation level of 80 Gy was the best dose for rearing of the pupal parasitoid,Dirhinus giffardii(Silvestri) (Hymenoptera: Chalcididae) owing to broad tolerances in the use of irradiation for the rearing of fruit-fly's parasitoids. Percentage parasitism byD. giffardiivaried with host pupal age, and the preference of the female parasitoid was lower on 48 h old host pharate pupae due to optimum size and mass of host. Present findings further revealed that the 24 h old host pupae ofB. zonatawere relatively more suitable for the maximum parasitism and progeny production ofD. giffardii. Parasitisms byD. giffardiiandT. daciwere significantly higher onB. zonatahost when parasitoids were released at a density of 3000 individuals per acre (7500 per hectares) than the other release rates of parasitoids for the management of fruit-flies in mango orchards. The implementation of these findings ought to help improve the mass production of parasitoids and the effectiveness of releases of biocontrol agents for control ofB. zonatain mango plantations. [ABSTRACT FROM PUBLISHER]