塔克拉玛干沙尘暴源区空气微生物群落的代谢特征

采用BIOLOG生态微平板(BIOLOG EcoPlateTM)技术,对采集自塔克拉玛干沙漠南北缘5个地区的空气样品进行研究,目的是了解空气微生物群落碳代谢功能的特点与差异.结果表明,5个地区空气样品的平均吸光度(AWCD)在培养10 d没有达到饱和且差异显著,AWCD值最高的为莎车县,和田县最低,分别为0.24和0.1;碳源利用水平表明这5个地区空气微生物对聚合物类碳源利用率最高,其次是碳水化合物、氨基酸类、羧酸类碳源,而酚类和胺类最低;主成分分析(PCA)发现有20种碳源与PC1显著相关,12种与PC2显著相关,并且这5个地区也被分为两类,和田和皮山聚为一类,乌恰、莎车和轮台聚为一类;典范对应分析(CCA)和相关分析表明一些非生物因素对空气微生物群落碳代谢强度和单一碳源的利用能力具有不同程度的影响,如风速、海拔、湿度等;进一步的研究也表明非生物因素对空气微生物群落利用的能力影响显著,其中β-甲基D-葡萄糖苷、D-半乳糖醛酸和腐胺的光密度值与纬度显著正相关(P<0.05),2-羟苯甲酸和α-D-乳糖与风速显著正相关(P<0.05),D-葡萄胺酸与气压显著正相关(P<0.05)且与海拔为显著负相关(P<0.05).综上可知,塔克拉玛干沙尘暴源区周边地区空气微生物群落碳代谢能力较低,呈现区域性特征,非生物因素显著影响空气微生物群落碳代谢强度及微生物群落对31种单一碳源的利用.

Metabolic Characteristics of Air Microbial Communities from Sandstorm Source Areas of the Taklamakan Desert

The aim was to compare the characteristics and the differences in carbon catabolic diversity of air samples collected from five locations that around the edge of Taklamakan desert. The characteristics and the differences of carbon metabolic profiles were detected by using the BIOLOG micro plate (BIOLOG EcoPlate). The results showed that the average well color development (AWCD) curve of all five samples did not reach clear saturation during the incubation time (10 days), but differences among them were significant. The highest AWCD value appeared in Shache and the lowest was in Hotan, which were 0.24 and 0.1, respectively. Carbon utilization showed that all samples exhibited high level of polymer, carbohydrates, amino acids and carboxylic acid; however, amine and the phenol compound were the lowest. Principal components analysis (PCA) indicated that twenty categories of carbon significantly related to PC1 and twelve categories for PC2. Hierarchical cluster analysis showed these five areas could be divided into 2 clusters: (1) Hotan, Pishan, (2) Shache, Luntai, Ulugqat. Canonical correspondence analysis (CCA) showed that those community functional diversities were highly affected by some environmental factors, such as wind speed, altitude, humidity. Further investigation by correlation analysis revealed that the microbial communities using single carbon source were significantly affected by abiotic factors, such as the utilization of beta-methyl-D-glucoside, D-galacturonic acid and putrescine had significantly positive correlation (P < 0.05) with latitude; 2-hydroxy benzoic acid and alpha-D-lactose significantly related to wind speed (P < 0.05); and D-glucosaminic acid was positive with air pressure, but it negatively correlated with altitude (P < 0.05). In conclusion,the carbon sources provided by BIOLOG EcoPlate were utilized slowly by air microbial communities; and the characteristics of the air community carbon catabolic along the edge of the Taklamakan desert revealed regional feature, which may be affected by environmental factors.