Department of Biochemistry, Cell and Molecular Biology, School of Biological Sciences, University of Ghana, Accra, Ghana.
Department of Applied Chemistry and Biochemistry, Faculty of Applied Sciences, University for Development Studies, Navrongo Campus, Navrongo, Ghana.
Microb Cell Fact. 2018 May 19;17(1):79. doi: 10.1186/s12934-018-0931-x.
Utilization of cocoa pod husks (CPH) in animal feed is hindered by the presence of theobromine, which is variably toxic to animals. Treatment of this agro-waste to remove theobromine, while preserving its nutrient content, would allow beneficial use of the millions of metric tonnes discarded annually. The aim of this study was to assess the suitability of selected theobromine-degrading filamentous fungi for use as bio-tools in degradation of theobromine in CPH.
The candidate fungi assessed in this study were an Aspergillus niger (AnTD) and three Talaromyces spp. (TmTD-1, TmTD-2, TvTD) isolates. All the fungi eliminated CPH theobromine, 0.15% w/w starting concentration, within 7 days of start of treatment, and were capable of degrading caffeine and theophylline. The fungi decreased CPH ochratoxin A content by 31-74%. Pectin was not detectable in fungus-treated CPH whereas parameters assessed for proximate composition were not affected.
The data provide ample evidence that the four isolates can be applied to CPH for the purpose of eliminating theobromine and decreasing ochratoxin A content without affecting nutrient profile. Comparatively, Talaromyces verruculosus TvTD was considered as most suitable for use as a bio-tool in detheobromination of CPH for animal feed.
可可荚壳（CPH）在动物饲料中的利用受到可可因的限制，可可因对动物具有不同程度的毒性。对这种农业废弃物进行处理以去除可可因，同时保留其营养成分，将允许每年丢弃的数百万公吨废物得到有益利用。本研究的目的是评估选定的可可因降解丝状真菌作为生物工具用于 CPH 中可可因降解的适用性。
在这项研究中评估的候选真菌是黑曲霉（AnTD）和三种塔玛多丝孢菌（TmTD-1、TmTD-2、TvTD）分离株。所有真菌都能在处理开始后的 7 天内消除 CPH 中的可可因（0.15%w/w 起始浓度），并能降解咖啡因和茶碱。真菌使 CPH 中赭曲霉毒素 A 的含量降低了 31-74%。经真菌处理的 CPH 中检测不到果胶，而评估的近缘组成参数不受影响。
这些数据充分证明，这四种分离株可用于 CPH，以去除可可因并降低赭曲霉毒素 A 的含量，而不影响营养成分。相比之下，塔玛多丝孢菌 TvTD 被认为是最适合用作生物工具，用于 CPH 脱可可因化以用于动物饲料。
