Metagenomics approach to identify lignocellulose-degrading enzymes in the gut microbiota of the Chinese bamboo rat cecum

BACKGROUND: Lignocellulose is considered a renewable organic material, but the industrial production of biofuel from lignocellulose is challenging because of the lack of highly active hydrolytic enzymes. The guts of herbivores contain many symbiotic microorganisms that have evolved to hydrolyze plant lignocellulose. Chinese bamboo rats mainly consume high-fiber foods, indicating that some members of the intestinal tract microbiota digest lignocellulose, providing these rats with the energy required for growth. RESULTS: Here, we used metagenomics to analyze the diversity and functions of the gut microbiota in Chinese bamboo rats. We identified abundant populations of lignocellulose-degrading bacteria, whose main functions involved carbohydrate, amino acid, and nucleic acid metabolism. We also found 587 carbohydrate-active enzyme genes belonging to different families, including 7 carbohydrate esterase families and 21 glycoside hydrolase families. The glycoside hydrolase 3, glycoside hydrolase 1, glycoside hydrolase 43, carbohydrate esterase 4, carbohydrate esterase 1, and carbohydrate esterase 3 families demonstrated outstanding performance. CONCLUSIONS: The microbes and enzymes identified in our study expand the existing arsenal of proficient degraders and enzymes for lignocellulosic biofuel production. This study also describes a powerful approach for targeting gut microbes and enzymes in numerous industries.

Atypical chronic myeloid leukaemia with trisomy 13: a case report / 中国医学科学杂志(英文版)

A typical chronic myeloid leukaemia (aCML), which shows both myeloproliferative and myelodysplastic features, is a type of myeloproliferative/myelodysplastic disease as defined by the World Health Organisation (WHO) classification of the myeloid neoplasms. Because of the presence of neutrophilic leukocytosis, aCML may resemble chronic myelogenous leukemia (CML). However, in contrast with CML, aCML does not have the Philadelphia chromosome or the bcr/abl fusion gene. With the continuous karotype analysis of aCML, several changes in the karyotype of aCML have been detected. However, few are recurring and no specific cytogenetic changes have been associated with aCML. Nonspecific cytogenetic abnormalities can be observed in 56%~82% of aCML cases. Although the most frequent abnormalities include trisomy 8 and del (20q), abnormalities involving other chromosomes such as 12, 13, 14, 17, and 19 have also been described. In this report we describe a case of aCML with trisomy 13.