Malathion is an organophosphate insecticide that has been widely used for both domestic and commercial agricultural purposes. However, malathion has the potential to produce toxic effects in mammalian systems. In this study,
AA112 which was isolated from soil using enrichment technique could utilize the malathion as a sole carbon source and a source of energy.
AA112 was able to grow in MSMPY medium containing 42.75 mg/ml malathion. However, the optimum concentration of malathion which supported the maximum bacterial growth was found to be 22. 8 mg/ml. Malathion was used as an initial source of energy and carbon when it was found without additional carbon sources (in MSM medium) while it was utilized as second source of energy and carbon in a nutrient-supplemented medium (in MSMPY medium). Moreover, lead acetate test indicated that malathion was first attacked at a sulphur site 1–2 hours after the start of incubation. TLC and IR analysis indicated that malathion was completely degraded into diethyl succinate, hydrogen sulphide and phosphates. Therefore a malathion degradation pathway was proporsed. The degradation of malathion is attributed to the genes located on the chromosome and at least three proteins of high molecular size might be involved in malathion utilization. Bacteria able to use malathion as a food source or metabolize its residues in the environment to inactive, less toxic, and harmless compounds, could be used in bioremediation of an environmental pollution caused by the pesticide.
Authors:N. Passricha, R. Batra, R. K Behl and V. K Sikka
A stock of disomic chromosome substitution (DCS) lines having specific chromosome of wheat variety C591 substituted in the background of rest of Chinese spring chromosomes, were used to analyze grain yield components as a function of enzyme activity of ADP–glucose pyrophosphorylase (AGPase), a starch biosynthesis enzyme in wheat grains. Associations between yield characteristics, grain growth rate (GGR) and AGPase enzyme activity of DCS lines suggested a major involvement of chromosome 3A, 4B, 7D and 2D in a temperature dependent manner. Assessment of AGPase assay at different developmental stages such as 14, 21, 28 days post anthesis (DPA) embodied that gene(s) for this enzyme are present on specific chromosomes and operate at different stages of grain development. The DCS line with 7D chromosome has a major contribution in determining the grain starch content. In this line, AGPase enzyme activity was highest at 21 DPA and was the most crucial determinant in its high GGR. Line 4B performed well at only early stage (14 DPA) suggesting that line 4B AGPase requires a lower temperature range for activation as compared to 7D line. Line 3A had substantially reduced (40%) test weights revealing the presence of few down-regulatory elements on chromosome 3A to reduce the activity of AGPase. The DCS line 2D showed higher test weights and grain number than all other lines ascribed to a consistent AGPase activity along with an efficient mechanism for translocation of photosynthates from source to sink. The chromosome 2D shows positive relation with yield attributes therefore, it can be employed to improve wheat productivity via analytical breeding programme.
Authors:Monika Bugno, Ewa Słota, Aldona Pieńkowska-schelling and Claude Schelling
Abe, S., Miyake, Y. I., Kageyama, S. I., Watanabe, G., Taya, K. and Kawakura, K. (1999): Deletion of the Sry region on the Y chromosome detected in case of equine gonadal hypoplasia (XY female) with abnormal