Silva Cristina Ferreira, Batista Luis Roberto, Abreu Lucas Magalhães, Dias Eustáquio Souza, Schwan Rosane Freitas
Departamento de Biologia, Universidade Federal de Lavras, UFLA, 37.200-000 Lavras, MG, Brazil.
Food Microbiol. 2008 Dec;25(8):951-7. doi: 10.1016/j.fm.2008.07.003. Epub 2008 Jul 11.
Bacteria, yeasts and filamentous fungi were isolated during natural coffee processing. Bacteria were isolated in greater numbers at the beginning of the fermentation, when the moisture of the coffee beans was around 68%. Gram-positive bacteria represented 85.5% of all bacteria isolated, and Bacillus was the predominant genus (51%). Gram-negative species of the genera Serratia, Enterobacter and Acinetobacter were also found. Approximately 22% of 940 randomly chosen isolates of microorganisms were yeasts. Debaryomyces (27%), Pichia (18.9%) and Candida (8.0%) were the most commonly found genera, and these three genera tended to appear more often as the fruit was fermented and dried. Aspergillus was the most abundant genus besides Penicillium, Fusarium and Cladosporium, with 42.6% of the total fungi isolates. The genera and species identified included members known to have pectinase and cellulase activities. Of the 10 organic acids analyzed and quantified in coffee beans, acetic and lactic acids may have been generated by microbial activity. Butyric acid was not detected in any sample.
在天然咖啡加工过程中分离出了细菌、酵母和丝状真菌。在发酵初期，咖啡豆湿度约为68%时，分离出的细菌数量更多。革兰氏阳性菌占所有分离出细菌的85.5%，芽孢杆菌是主要属（51%）。还发现了沙雷氏菌属、肠杆菌属和不动杆菌属的革兰氏阴性菌。在随机挑选的940株微生物分离株中，约22%为酵母。德巴利酵母属（27%）、毕赤酵母属（18.9%）和假丝酵母属（8.0%）是最常见的属，随着果实发酵和干燥，这三个属往往出现得更频繁。除青霉属、镰刀菌属和枝孢菌属外，曲霉属是最丰富的属，占真菌分离株总数的42.6%。鉴定出的属和种包括已知具有果胶酶和纤维素酶活性的成员。在咖啡豆中分析和定量的10种有机酸中，乙酸和乳酸可能是由微生物活动产生的。在任何样品中均未检测到丁酸。
