Ben Guerrero Emiliano, Soria Marcelo, Salvador Ricardo, Ceja-Navarro Javier A, Campos Eleonora, Brodie Eoin L, Talia Paola
Instituto de Biotecnología, Centro de Investigación en Ciencias Veterinarias y Agronómicas, Centro Nacional de Investigaciones Agropecuarias - Instituto Nacional de Tecnología Agropecuaria Castelar Hurlingham, Argentina.
Instituto de Investigaciones en Biociencias Agrícolas y Ambientales-Consejo Nacional de Investigaciones Científicas y Técnicas, Cátedra de Microbiología Agrícola, Facultad de Agronomía, Universidad de Buenos Aires Buenos Aires, Argentina.
Front Microbiol. 2016 Dec 27;7:2093. doi: 10.3389/fmicb.2016.02093. eCollection 2016.
Cotton boll weevils, , are omnivorous coleopteran that can feed on diets with different compositions, including recalcitrant lignocellulosic materials. We characterized the changes in the prokaryotic community structure and the hydrolytic activities of larvae fed on different lignocellulosic diets. larvae were fed on three different artificial diets: cottonseed meal (CM), Napier grass (NG) and corn stover (CS). Total DNA was extracted from the gut samples for amplification and sequencing of the V3-V4 hypervariable region of the 16S rRNA gene. Proteobacteria and Firmicutes dominated the gut microbiota followed by Actinobacteria, Spirochaetes and a small number of unclassified phyla in CM and NG microbiomes. In the CS feeding group, members of Spirochaetes were the most prevalent, followed by Proteobacteria and Firmicutes. Bray-Curtis distances showed that the samples from the CS community were clearly separated from those samples of the CM and NG diets. Gut extracts from all three diets exhibited endoglucanase, xylanase, β-glucosidase and pectinase activities. These activities were significantly affected by pH and temperature across different diets. We observed that the larvae reared on a CM showed significantly higher activities than larvae reared on NG and CS. We demonstrated that the intestinal bacterial community structure varies depending on diet composition. Diets with more variable and complex compositions, such as CS, showed higher bacterial diversity and richness than the two other diets. In spite of the detected changes in composition and diversity, we identified a core microbiome shared between the three different lignocellulosic diets. These results suggest that feeding with diets of different lignocellulosic composition could be a viable strategy to discover variants of hemicellulose and cellulose breakdown systems.
棉铃象甲是杂食性鞘翅目昆虫，能够以不同成分的食物为食，包括难降解的木质纤维素材料。我们对取食不同木质纤维素食物的棉铃象甲幼虫的原核生物群落结构变化和水解活性进行了表征。用三种不同的人工饲料喂养棉铃象甲幼虫：棉籽粕（CM）、象草（NG）和玉米秸秆（CS）。从肠道样本中提取总DNA，用于16S rRNA基因V3 - V4高变区的扩增和测序。变形菌门和厚壁菌门在肠道微生物群中占主导地位，其次是放线菌门、螺旋体门以及CM和NG微生物群落中少数未分类的门。在CS喂养组中，螺旋体门成员最为普遍，其次是变形菌门和厚壁菌门。Bray - Curtis距离表明，CS群落的样本与CM和NG饲料的样本明显分开。所有三种饲料的肠道提取物均表现出内切葡聚糖酶、木聚糖酶、β - 葡萄糖苷酶和果胶酶活性。这些活性在不同饲料中受pH和温度的显著影响。我们观察到，以CM饲养的幼虫表现出的活性明显高于以NG和CS饲养的幼虫。我们证明肠道细菌群落结构因饲料组成而异。成分更具变化性和复杂性的饲料，如CS，比其他两种饲料表现出更高的细菌多样性和丰富度。尽管检测到组成和多样性的变化，但我们在三种不同的木质纤维素饲料中鉴定出了一个核心微生物群。这些结果表明，用不同木质纤维素组成的饲料喂养可能是发现半纤维素和纤维素分解系统变体的可行策略。
