英国科学家亚历山大·弗莱明发现的青霉素拯救了无数人的生命，但英国研究人员最近发现，弗莱明最初发现的产生青霉素的真菌不是人们长期认为的种类，它一直被叫错了80多年。
弗莱明1928年在伦敦圣玛丽医学院工作时发现，一种真菌所分泌的物质可以杀死细菌，这种物质就是后来被广泛使用的青霉素。此后，科学界找到了能产生青霉素的“产黄青霉菌”，并一直认为这就是弗莱明最初发现的菌种。
圣玛丽医学院保留了弗莱明的真菌样本，该校并入英国帝国理工学院后，这些样本也一直保存了下来。帝国理工学院11月21日发布公报说，该校研究人员对这些样本进行了基因分析，发现它并不是标准的“产黄青霉菌”，而是与之非常相近的一个菌种，由于之前没有注意到，这个菌种还没有得到命名。
研究人员请全球各地的同行提供了当地搜集到的产黄青霉菌样本，通过基因分析发现，虽然它们长期被认为是一个物种，但“产黄青霉菌”的名下可能有四个不同的物种，它们非常相似，如果不使用基因手段难以辨别出来。
参与研究的丹尼尔·亨克说，这说明弗莱明非常幸运，他不仅发现的是一种能产生青霉素的真菌，其他研究者后续分离出的也正好是有相同功能的菌种，如果碰上了别的菌种而无法重复实验结果，那么也许会有别的人在其他研究中报告发现青霉素。
他还表示，这项发现说明这一类真菌有很强的生物多样性，这对研制新药物来说是个好消息，可以探索这些青霉素的“亲戚”是否能产生新的药用物质。相关研究报告已经发表在学术刊物《分子生态学》上。（生物谷 Bioon.com）
doi:10.1111/j.1365-294X.2011.05244.x
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Speciation despite globally overlapping distributions in Penicillium chrysogenum: the population genetics of Alexander Fleming’s lucky fungus
D. A. HENK, C. E. EAGLE, K. BROWN, M. A. VAN DEN BERG, P. S. DYER, S. W. PETERSON, M. C. FISHER
Keywords:Alexander Fleming;asexual;microsatellite;Penicillium flemingii;speciationAbstractEighty years ago, Alexander Fleming described the antibiotic effects of a fungus that had contaminated his bacterial culture, kick starting the antimicrobial revolution. The fungus was later ascribed to a putatively globally distributed asexual species, Penicillium chrysogenum. Recently, the species has been shown to be genetically diverse, and possess mating‐ ype genes. Here, phylogenetic and population genetic analyses show that this apparently ubiquitous fungus is actually composed of at least two genetically distinct species with only slight differences detected in physiology. We found each species in air and dust samples collected in and around St Mary’s Hospital where Fleming worked. Genotyping of 30 markers across the genome showed that preserved fungal material from Fleming’s laboratory was nearly identical to derived strains currently in culture collections and in the same distinct species as a wild progenitor strain of current penicillin producing industrial strains rather than the type species P. chrysogenum. Global samples of the two most common species were found to possess mating‐ ype genes in a near 1:1 ratio, and show evidence of recombination with little geographic population subdivision evident. However, no hybridization was detected between the species despite an estimated time of divergence of less than 1 MYA. Growth studies showed significant interspecific inhibition by P. chrysogenum of the other common species, suggesting that competition may facilitate species maintenance despite globally overlapping distributions. Results highlight under‐\recognized diversity even among the best‐known fungal groups and the potential for speciation despite overlapping distribution.
