Journal of Ecosystem & Ecography
Open Access

Abstract

In the co-evolution, beneficial intestinal and fecal microorganisms (Fecal Microbiota) play an important role in digestion and absorption of food, immunity, resistance to pathogens, and health maintaining of their hosts. In order to provide new sources for discovering new leader compounds of drugs, the diversity and bioactivities of cultivable actinobacteria of animal feces have been studied. Fecal samples of 7 species of carnivorous, omnivorous and phytophagous animal were collected from Yunnan Wild Animal Park. The purified cultures of actinobacteria were isolated from these samples using 5 media. The 16S rRNA gene sequences of 623 selected strains were analyzed, and the phylogenetic analysis was carried out. The isolates were identified at a species level. The study results showed that actinomycete community of each animal feces was different from each other. Thirteen genera of actinobacetria were identified from feces of both Giant panda ( Ailuropoda melanoleuca ) and tiger ( Panthera tigris tigris ). Total 31 genera of actinobacteria were identified from the 7 species of animal feces. Members of Streptomyces were the first preponderant microbe, cfu/g of dried samples were up to 10 9 , and distributed in all 7 species of animals. 39 species of the genus were identified, and Streptomyces albus, S. albidoflavus, S. griseus, S. hygroscopicus, S. rutgersensis, S. tendae, and S. violaceoruber etc., were occurred a high frequency. Members of Rhodococcus and Arthrobacter were identified in 6 species animals. Rhodococcus coprophilus , Rh. corynebacterioides, Rh. corynebacterioides, Rh. equi, Rh. pyridinivorans and Rh. zopfii were occurred at high frequency. Microbacterium was identified from 5 species of animal feces. These results indicated that, first, members of the genus Streptomyces and Order Micrococcales were the widest distribution and the largest amount; second, composition of actinobacteria with Chemotype IV to IX and globose and bacilliform shapes, specially Order Micrococcales , were the richest diversity, and occurred a high frequency in most part of tested animal feces. These are distinct features of cultivable fecal actinomycete community differing from those in soil, plant, and marine environment. Selective isolation methods for fecal actinomycetes, especially un-known actinomycetes, are very important. A large number of Gram negative bacteria, fungi and even known actinomycetes in animal feces are a main problem for selective isolation of un-known actinobacteria. In order to eliminate these troubles, and obtain much more un-known actinobacteria for discovering novel lead compounds, sampling and isolation methods are key points. Based on many tests in our laboratory, first, it is best to collect fresh fecal samples from wild animals living in original forest and original habitats (this is not easy); second, the fresh samples have to dry at 25-28 º C for 7 to 10 days; third, the dried samples have to be treated at 80 º C for 60 min, and the fecal suspension should be treated with ultrasound wave for 40? at 150W before isolation; fourth, potassium bichromate 50 mg and 5 mg penicillin, or nystatin 50 mg, nalidixic acid 20 mg and 5 mg penicillin for 1000 ml medium, as inhibitors, have to be added in the isolation medium for inhibiting fungi and Gram negative bacteria; Fifth, in general, the samples should be diluted to 10 -5 , 10 -6 , and 10 -7 , and the optimum dilution concentration for each animal fecal sample should be tested before and all alone; sixth, YIM 212, YIM 171 and HV medium were better for isolation of fecal actinobacteria.

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