产纤维素菌株的分离鉴定及产量相关性

Isolation, identification and yield correlation of cellulose-producing strains

摘要:

【背景】细菌纤维素是一种性能优异的新型天然生物纳米材料，但其发酵产量低、生产成本高，尚未得到大规模生产与应用。【目的】自然选育细菌纤维素高产菌株，并探索菌株产量与菌落形态、水果来源、菌株种属之间的关联。【方法】从15个不同种类的576份腐烂水果中自然选育产纤维素菌株，并按菌落形态进行分类。静置培养筛选高产纤维素菌株，并对所得菌株进行16S rRNA基因测序，鉴定其种属。【结果】获得134株产纤维素菌株，其中一株分离自芒果的汉氏驹形杆菌(Komagataeibacter hansenii)产量最高，为11.24 g/L。所得菌株按菌落形态可分为10个类别，高产纤维素菌株形态共同特征为黄色、圆形、边缘整齐或不规则、表面粗糙或褶皱、凸起(形态4、5、9)。苹果和梨来源中分离得到的菌株菌落形态多样性丰富，高产纤维素菌株的水果来源中芒果所占比值最高，其次为梨和苹果。所有菌株鉴定为5个属13个种，包含了醋酸杆菌属(Acetobacter)、驹形杆菌属(Komagataeibacter)、葡糖醋杆菌属(Gluconacetobacter)、沙雷氏菌属(Serratia)和乳酸杆菌属(Lactobacillus)，其中高产纤维素菌株集中分布于汉氏驹形杆菌(K. hansenii)和中间驹形杆菌(K. intermedius)。【结论】筛到的菌株多样性丰富，并且得到多株高产纤维素菌株，其传代稳定性好，丰富了细菌纤维素生产菌株的来源。分析所得菌株产量与菌落形态、水果来源之间的关系可以为今后菌株筛选工作提供参考。

Abstract:

[Background] Bacterial cellulose is a new type of natural bio-nanomaterials with excellent properties, but it has not yet been achieved production and application in large-scale because of the low fermentation yield and high production cost. [Objective] We naturally selected and bred cellulose high-yield strains, and explored the relationship between the strain yield, colony morphology, fruits source and strains species. [Methods] Naturally bred cellulose-producing strains were selected from a total of 576 rotten fruits covering 15 species, and classified by colony morphologies. High-yield cellulose strains were screened by static culture, and the 16S rRNA gene region of the strains was sequenced to identify their species. [Results] 134 cellulose-producing strains were obtained. The best strain Komagataeibacter hansenii was isolated from mango with the yield 11.24 g/L. All strains was classified into 10 categories according to the colony morphology. The common characteristics of high-yield cellulose colonial morphologies were yellow, round, raised, neat or irregular edges and rough or wrinkled surface (morphology 4, 5, 9). The colonies’ morphological diversity of strains isolated from apple and pear were abundant. Most of high-yield cellulose strains were mango-derived, followed by pears and apples. All strains were identified as 5 genera and 13 species, including Acetobacter, Komagataeibacter, Gluconacetobacter, Serratia, and Lactobacillus, in which highly productive cellulose strains were concentrated in K. hansenii and K. intermedius. [Conclusion] The screened strains are rich in diversity, and a number of high-yield cellulose strains are obtained, which have good heredity stability and greatly enrich the source of bacterial cellulose production strains. Analysis of the relationship between the yield of the obtained strains with the colony morphology and fruit source may offers reference for future screening work.