search
for
 About Bioline  All Journals  Testimonials  Membership  News  Donations


African Journal of Food, Agriculture, Nutrition and Development
Rural Outreach Program
ISSN: 1684-5358
EISSN: 1684-5374
Vol. 12, No. 6, 2012
Bioline Code: nd12080
Full paper language: English
Document type: Research Article
Document available free of charge

African Journal of Food, Agriculture, Nutrition and Development, Vol. 12, No. 6, 2012

 en LIPOLYTIC ACTIVITY OF SOME FUNGAL SPECIES ON CASTOR OIL
Negedu, A; Ameh, JB; Umoh, VJ & Atawodi, SE

Abstract

Castor seed is important because of the castor oil content (40 – 57%). The oil enjoys tremendous world demand in the pharmaceutical, paint, cosmetics, textile, leather, lubricant, chemical, plastic, fibre, automobile and engineering industries. Castor oil, aside being a renewable resource, it is biodegradable and eco-friendly. Agricultural products are natural habitats of fungi and these materials contain cellulose, hemi-cellulose, starch, oils and other complex organic compounds. The ability of the fungi to exist in these environments largely depends on their ability to produce enzymes capable of breaking down the various organic materials to provide their nutrients. Castor seeds and castor oil are good sources of nutrients for fungal growth and development. Fungi are capable of producing lipases which can hydrolyze fats or oils to fatty acids thereby increasing the free fatty acids of the produce and this is a deteriorating effect. Lipid degradation takes place when seeds or their oils are damaged by improper storage conditions or are exposed to certain microorganisms. Studies were carried out on the ability of nine fungal species namely: Aspergillus tamarii check for this species in other resources Aspergillus chevallieri check for this species in other resources , Penicillium chrysogenum check for this species in other resources , Cephaliophora irregularis check for this species in other resources , Syncephalastrum racemosum check for this species in other resources , Aspergillus flavus check for this species in other resources , Aspergillus ruber check for this species in other resources , Aspergillus terreus check for this species in other resources and Aspergillus niger check for this species in other resources to produce extracellular lipases in stationary liquid medium using quantitative and qualitative indices including, dry mycelia mass, free fatty acid and peroxide values. These studies showed that all the mould species exhibited lipolytic activity to varying levels as confirmed by formation of blue halo round the fungal colonies. The highest level of lipolytic activity (96.88% ± 1.12%) was produced by Aspergillus tamari. which was also characterized by highest mycelia dry yield (2.54 mg/40ml ± 0.20 mg/40ml), while Cephaliphora irregularis produced the least lipolytic activity (3.10 % ± 0.18%). The highest peroxide value (38.1 meq/kg ± 1.17meq/kg) was obtained in the medium inoculated with Aspergillus tamarii while the least (6.20 meq/kg ± 0.58)meq/kg was with Aspergillus terreus after 30 days of storage. The study showed that Aspergillus tamarii and Aspergillus flavus grew well and readily caused lipolytic activity when cultured in medium containing castor oil as the only carbon source, suggesting that these fungal species contributed significantly to castor oil bio-deterioration.

Keywords
Castor, Seeds, Oil, Fungi, Deterioration

 
© Copyright 2012 - African Journal of Food Agriculture, Nutrition and Development
Alternative site location: http://www.ajfand.net/

Home Faq Resources Email Bioline
© Bioline International, 1989 - 2017, Site last up-dated on 16-Oct-2017.
Site created and maintained by the Reference Center on Environmental Information, CRIA, Brazil
System hosted by the Internet Data Center of Rede Nacional de Ensino e Pesquisa, RNP, Brazil