Vol 3, No 2 (2018)

Table of Contents

EDITORIAL

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Ji-Dong Gu
DOI:10.18063/AEB.2016.01.001

Abstract

N/A

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RESEARCH ARTICLES

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Lin Na Du, Ke Ke Pan, Gang Li, Yu Yi Yang, Fang Cheng Xu

Abstract

Microbial decolorization has been investigated extensively. Various microbes have been studied for their dye removing capability; however, microbial decolorizer with a strong environmental adaptability and wide substrate spectrum is of great potential for its possible practical application. Therefore, in this study, Aeromonas sp. DH-6, a wide dye spectrum decolorizer, was investigated in terms of its use for Malachite Green (MG) remediation. Results indicated that most of carbon sources have no effect on decolorization, while the nitrogen sources of beef extract and yeast extract could enhance MG decolorization significantly. Among the tested metal ions, Cu2+, Fe2+, and Zn2+ could significantly inhibit decolorization. Moreover, the strain showed a very stable and efficient decolorization performance in the pH of 5.0-10.0 and at 20-40oC. Besides, it could almost completely decolorize MG at concentrations ≤ 1000 mg/L within 36 h. Based on UV-visible, GC-MS, and FTIR analysis, biodegradation of MG by the strain DH-6 was confirmed and data showed that MG was decomposed into 4-(Dimethylamino)benzophenone and other metabolites containing –C=O, –NH, and –OH groups. Enzyme analysis showed that tyrosinase, laccase, LiP, NADH-DCIP reductase, and MG reductase might be involved in MG degradation by the strain DH-6. Overall, the results demonstrated that the strain DH-6 will have an effective use as an alternative in MG bioremediation.


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Zhao Yanting, Ye Lin, Duan Cuilan, Zhang Xu-xiang

Abstract

The lactic acid bacteria (LAB) play a crucial role in the health of aquatic animals through controlling and competing with pathogens. In this study, based on the high-throughput sequencing of 16S rRNA gene amplicons, we examined the LAB in the gut of freshwater shrimp (Macrobrachium nipponense) and their living environments (sediment and pond water) and analyzed the correlations between the shrimp production and abundance of LAB. A high diversity and abundance of LAB (27 genera) were observed among the freshwater shrimp gut samples, and the results indicated that dissolved oxygen and temperature could affect the LAB community in the shrimp gut. In addition, share and unique LAB among the shrimp gut, sediment and pond water were further analyzed. Linear regression analysis showed that the relative abundance of LAB was positively correlated with the levels of shrimp production. Moreover, comparison of the LAB community among different animals indicated that some LAB in shrimp gut may also play a beneficial role in fish, houseflies, pig and other animals. Collectively, this study provides comprehensive information for better understanding LAB in shrimp gut and their environments and further improving the ecological management of aquatic ecosystems regarding the application of probiotics and disease prevention.


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REVIEW ARTICLES

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Ji-Dong Gu

Abstract

Coastal ecosystem is important because it bridges ocean and land. The brackish water receiving nutrients originated from land may nourish heterotrophic bacteria including Vibrio species, some of which may pose potential hazards to the public, marine lives and migratory birds in the coastal environment. A rich diversity of Vibrios is evident in the coastal and open oceans, but information on their ecophysiological adaptation and survival is still very limited. Their important roles in the geobiochemical cycles of nutrients have not been exolored adequately. In addition, it also been recently discovered that these Vibrios harbor a very rich of plasmids of various sizes with little knowledge on their function to the hosts. This information deserves attention in Vibrio ecology and their role in the various ecosystems for a better understanding of their survival and physiological function. 


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