School of Biology, Costa Rican Institute of Technology, Cartago, Costa Rica.
Bioprocess Unit, National Center for Biotechnological Innovations of Costa Rica - CENIBiot, San José, Costa Rica.
Curr Microbiol. 2020 Jun;77(6):943-952. doi: 10.1007/s00284-020-01886-8. Epub 2020 Jan 25.
Tropical oleaginous seeds are an unexplored source for the discovery of novel lipolytic microorganisms, which could be applied to the bioremediation of agro-industrial oily wastes and solve numerous environmental issues. Such wastes hold potential to be revalorized towards a variety of products through microbial bioremediation. In this study, we investigate the microbial diversity and lipase activity from bacterial and fungal isolates obtained from the oil seeds of Elaeis guineensis, Ricinus communis, and Jatropha curcas L. from Costa Rica. A total of 27 strains were confirmed as lipase-producing strains via fluorogenic and colorimetric agar plate assays. The diversity of the isolates comprises 12 fungal ascomycetes from the genera Aspergillus and Fusarium and 15 bacterial isolates classified into four genera: Serratia, Proteus, Pseudomonas, and Bacillus. Microbial isolates from E. guineensis showed the highest diversity of lipolytic microorganisms (6 genera) followed by J. curcas (4 genera) and R. communis (2 genera). Isolates showing the highest activity in agar plates were tested further by submerged fermentation and the specific lipase activity was measured with 4-nitrophenyl laurate as substrate. Accordingly, the highest specific lipase activity was demonstrated by Bacillus pumilus B5 (24.98 U mg), Serratia marcescens B10 (17.65 U mg), Pseudomonas mendocina B16 (8.62 U mg), and Bacillus pumilus B1 (5.72 U mg) in submerged fermentation. These findings indicate the presence of a specialized microbial diversity in tropical oil seeds and highlight their potential to be applied in the bioremediation of agro-industrial oily wastes.
热带油脂种子是发现新型脂肪酶微生物的未开发来源，这些微生物可应用于农业工业含油废物的生物修复，解决众多环境问题。通过微生物生物修复，此类废物有可能被重新利用生产各种产品。在这项研究中，我们调查了从哥斯达黎加的油棕、蓖麻和麻疯树的油籽中分离出的细菌和真菌的微生物多样性和脂肪酶活性。通过荧光和比色琼脂平板测定，共有 27 株被确认为产脂肪酶菌株。分离株的多样性包括来自曲霉属和镰刀菌属的 12 种真菌和 15 种细菌分离株，分为 4 个属：沙雷氏菌属、普罗维登斯菌属、假单胞菌属和芽孢杆菌属。油棕来源的微生物分离株显示出最高多样性的脂肪酶微生物（6 个属），其次是麻疯树（4 个属）和蓖麻（2 个属）。在琼脂平板上显示出最高活性的分离株进一步通过深层发酵进行测试，并使用 4-硝基苯棕榈酸酯作为底物测量特定的脂肪酶活性。相应地，芽孢杆菌 B5（24.98 U mg）、粘质沙雷氏菌 B10（17.65 U mg）、门多萨假单胞菌 B16（8.62 U mg）和芽孢杆菌 B1（5.72 U mg）在深层发酵中表现出最高的特定脂肪酶活性。这些发现表明热带油籽中存在特殊的微生物多样性，并强调了它们在农业工业含油废物生物修复中的应用潜力。
