Waste to wealth: Production of oxytetracycline using streptomyces species from household kitchen wastes of agricultural produce
The production of oxytetracycline by Streptomyces speibonae OXS1 in solid-state fermentation from cocoyam peels (household kitchen wastes of agricultural produce) was investigated. The proximate analyses of peels of the two cocoyam species showed that Colocasia esculenta had higher protein (1.39%) and fibre (15.70%) contents than Xanthosoma esculenta with protein and fibre contents of 0.91 and 6.95%, respectively. Oxytetracycline was detected on the first day of fermentation and reached its peak on the third day. The optimum moisture content of the substrate for the production of the antibiotic was 65% at room temperature, and a pH range of 5.8 to 6.0. Seven days fermentation gave higher biomass weight (140.86 g) for C. esculenta than X. esculenta (101.62 g), indicating a possible higher presence of the anticipated fermentation product (oxytetracycline) in the fermentation jar of the former. Bioassay for determination of the antibiotic presence confirmed that oxytetracycline was present in both species of the cocoyam peels, but in higher amounts in C. esculenta at every instance. Cocoyam peels- a common household kitchen wastes, that otherwise would have become breeding foci for disease pathogens, are by the outcome of this study shown to be bioconvertible into substrates for the production of oxytetracyclines, an important class of antibiotics that are vitally useful both for the health care delivery system and agro-poultry industry, etc. The fact that cocoyam peels could become very useful substrate for the production of this very important class of drugs is indeed a big plus both for the pharmaceutical industry and public health programme of environmental health and safety. This application also offers an alternative waste management option for this class of household kitchen wastes of agricultural produce that is usually present in great abundance in our environment. By sodoing, these wastes with great potential for environmental degradation, pollution and disease causation, are turned into raw materials for the pharmaceutical industry, thus, becoming a veritable resource for industrial growth, with possible positive impacts of this exploitation on job and wealth creations for national economic prosperity. Added to these are the public health impacts of a safer and healthier environment likely to be secured through the indirect waste management option so offered.
Key words: Oxytetracycline production, streptomyces, household kitchen wastes.