Assis Danyelle Alves Martins, Rezende Rachel Passos, Dias João Carlos Teixeira
Laboratório de Monitoramento Ambiental/Laboratório de Biotecnologia de Microrganismos, Centro de Biotecnologia e Genética, Universidade Estadual de Santa Cruz (UESC), 45662-900 Ilhéus, BA, Brazil.
ISRN Biotechnol. 2014 Mar 12;2014:909601. doi: 10.1155/2014/909601. eCollection 2014.
Modern techniques involving molecular biology, such as metagenomics, have the advantage of exploiting a higher number of microorganisms; however, classic isolation and culture methods used to obtain antimicrobials continue to be promising, especially in the isolation of Actinobacteria, which are responsible for the production of many of these compounds. In this work, two methodologies were used to search for antimicrobial substances-isolation of Actinobacteria and metagenomics of the Atlantic Rainforest soil and of the cultivation of cocoa intercropped with acai berry in the Atlantic Rainforest. The metagenomic libraries were constructed with the CopyControl Fosmid Library kit EPICENTRE, resulting in a total of 2688 clones, 1344 of each soil sample. None of the clones presented antimicrobial activity against the microorganisms tested: S. aureus, Bacillus subtilis, and Salmonella choleraesuis. A total of 46 isolates were obtained from the isolation of soil Actinobacteria: 24 isolates from Atlantic Rainforest soil and 22 isolates from the intercrop cultivation soil. Of these, two Atlantic Rainforest soil isolates inhibited the growth of S. aureus including a clinical isolate of S. aureus MRSA-a promising result, since it is an important multidrug-resistant human pathogen.
涉及分子生物学的现代技术，如宏基因组学，具有利用更多微生物的优势；然而，用于获取抗菌剂的经典分离和培养方法仍然很有前景，特别是在放线菌的分离方面，放线菌是许多此类化合物的产生者。在这项工作中，使用了两种方法来寻找抗菌物质——从大西洋雨林土壤中分离放线菌和进行宏基因组学研究，以及在大西洋雨林中种植与阿萨伊浆果间作的可可。使用EPICENTRE的CopyControl Fosmid Library试剂盒构建宏基因组文库，共得到2688个克隆，每个土壤样本各1344个。没有一个克隆对测试的微生物——金黄色葡萄球菌、枯草芽孢杆菌和猪霍乱沙门氏菌表现出抗菌活性。从土壤放线菌的分离中总共获得了46株分离物：24株来自大西洋雨林土壤，22株来自间作种植土壤。其中，两株来自大西洋雨林土壤的分离物抑制了金黄色葡萄球菌的生长，包括一株耐甲氧西林金黄色葡萄球菌临床分离株——这是一个很有前景的结果，因为它是一种重要的多重耐药人类病原体。
