Lugauskas Albinas, Raila Algirdas, Zvicevicius Egidijus, Railiene Marija, Novosinskas Henrikas
Laboratory of Biodeterioration Research, Institute of Botany, Vilnius, Lithuania.
Ann Agric Environ Med. 2007;14(1):173-86.
During the meteorologically contrasting period of 2003-2005, the contamination of winter wheat, malt barley and fodder barley grain with micromycetes during grain harvesting and preparation for storage was investigated. Micromycetes of over 70 species ascribed to 16 genera were isolated and identified, the density of their populations in grain was determined. Micromycetes with a population density of >50% were attributed to dominant species. Short biological characteristic, ecological peculiarities of the dominating micromycetes are provided; factors determining intensity of their development and abilities to synthesise and excrete toxic metabolites are indicated. The importance of grain drying for stabilisation of its contamination with micromycete propagules is highlighted. It is noted that in grain dried in shaft dryer using air at 90 degrees C the number of cfu (colony forming units) was reduced from 2.2 to 8.2 times. When active ventilation is applied, conditions favourable for the development of micromycetes remain longest in the upper layers of the mound. The airflow passing through the layer of damp grain inhibits the development of micromycetes, but an increase of comparative air flow for more than 500 m3x(txh)(-1) did not reduce the abundance of micromycete cfu. After drying Alternaria alternata, Fusarium avenaceum, F. culmorum, Penicillum verrucosum dominated in wheat grain; Aspergillus flavus, Bipolaris sorokiniana, Fusarium chlamydosporum, F. culmorum, F. tricinctum in malts barley grain; Fusarium avenaceum, F. culmorum, F. tricinctum, Alternaria alternata in fodder barley grain. It has been determined that all micromycetes recorded on grain after drying are potential producers of toxic metabolites, i.e. are hazardous to human health.
在2003 - 2005年气象条件差异较大的时期，对冬小麦、麦芽大麦和饲料大麦在收获及储存准备过程中被微真菌污染的情况进行了调查。分离并鉴定出了属于16个属的70多种微真菌，测定了它们在谷物中的种群密度。种群密度>50%的微真菌被归为优势种。提供了优势微真菌的简短生物学特性和生态特性；指出了决定其生长强度以及合成和分泌有毒代谢物能力的因素。强调了谷物干燥对于稳定其被微真菌繁殖体污染情况的重要性。注意到在使用90摄氏度空气的竖炉干燥机中干燥的谷物中，菌落形成单位（cfu）数量减少了2.2至8.2倍。当采用主动通风时，有利于微真菌生长的条件在粮堆上层持续的时间最长。通过潮湿谷物层的气流会抑制微真菌的生长，但比较气流增加超过500立方米×（吨·小时）⁻¹并不会降低微真菌cfu的数量。干燥后，冬小麦籽粒中链格孢、燕麦镰孢、禾谷镰孢、疣孢青霉占主导；麦芽大麦籽粒中黄曲霉、索氏炭疽菌、厚垣镰孢、禾谷镰孢、三线镰孢占主导；饲料大麦籽粒中燕麦镰孢、禾谷镰孢、三线镰孢、链格孢占主导。已确定干燥后谷物上记录的所有微真菌都是有毒代谢物的潜在产生者，即对人类健康有害。
