The Potential of Naturally occurring Soil Micro-organisms in Degrading Endosulfan-α, β and Lindane: A Case Study of Qurashi Pesticides Store (Hasahessa) - Sudan

No Thumbnail Available
Abdalla, Tumador Mohammed Ali
Journal Title
Journal ISSN
Volume Title
The current research consists of laboratory studies on soil microorganisms, bacteria and actinomycetes, naturally occurring in Qurashi pesticides store near Hasahessa, central Sudan, and surrounding areas (cotton field and fallow land). These microorganisms are known to act in degradation of pesticides. Qurashi pesticides store was selected to represent a highly contaminated soil, the two other soil sites (cotton and fallow) were used to represent soil of relatively less contamination. Three trails were executed viz; the first trail was to survey and counts of naturally occurring microorganisms in the soil, using three selective medias, viz; meat peptone agar (MPA) media, for organic nitrogen using bacteria; starch ammonium agar (SAA) media, for inorganic nitrogen using bacteria and actinomycetes; and nitrate agar (NA) media for microorganisms capable of growing on poor media. The second trail was to study the impact of adding three of chlorinated hydrocarbon insecticides (endosulfan a, b and Lindane) on the types and counts of bacteria and actinomycetes present in the three soil samples. While the third trail was to investigate the potential of these microorganisms in degradation and shorting, the half lives of the candidate insecticides. The result of the survey indicated the presence of autotrophic and heterotrophic microorganisms (bacteria and actinomycetes). Two types of bacteria (Arthobacter and Mycobacterium) and actinomycetes (Micromonospora) these are capable of growing on poor media, while Nocardia was not detected in the three soil types. The actinomycetes Micromonospora and Arthobacterium were more prevalent in fallow soil, while Mycobacterium was more prevalent in store soil. The addition of candidate pesticides to the three types of media resulted an increase in the counts of all microorganisms irrespective of their source. The highest increase in the general and specific counts of actinomycetes, probably Micromonospora, seems to be associated with endosulfan b. However, bacteria responses to added chemicals varied according to the soil source. This is probably indicating that one type of actinomycetes may be present, while various genus or strains of bacteria may be present in the three sites of soil. Further investigations are needed to verify this. Incubation with store soil extract shortened the half lives of endosulfan a, b and lindane by 62%, 70% and 79% respectively. Various aspects of microbial degradation of chlorinated hydrocarbon pesticides were discussed and future projects of research were outlined
December 2004