Microbial Community of Tannery Wastewater Involved in Nitrification Revealed by Illumina MiSeq Sequencing

( Xiaojian Ma ),( Chongde Wu ),( Huang Jun ),( Rongqing Zhou ),( Bi Shi ) 한국미생물생명공학회(구 한국산업미생물학회) 2018 Journal of microbiology and biotechnology Vol.28 No.7

The aim of this study was to investigate the microbial community of three tannery wastewater treatment plants (WWTPs) involved in nitrification by Illumina MiSeq sequencing. The results showed that highly diverse communities were present in tannery wastewater. A total of six phyla, including Proteobacteria (37-41%), Bacteroidetes (6.04-16.80), Planctomycetes (3.65- 16.55), Chloroflexi (2.51-11.48), Actinobacteria (1.91-9.21), and Acidobacteria (3.04-6.20), were identified as the main phyla, and Proteobacteria dominated in all the samples. Within Proteobacteria, Beta-proteobacteria was the most abundant class, with the sequence percentages ranging from 9.66% to 17.44%. Analysis of the community at the genus level suggested that Thauera, Gp4, Ignavibacterium, Phycisphaera, and Arenimonas were the core genera shared by at least two tannery WWTPs. A detailed analysis of the abundance of ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) indicated that Nitrosospira, Nitrosomonas, and Nitrospira were the main AOB and NOB in tannery wastewater, respectively, which exhibited relatively high abundance in all samples. In addition, real-time quantitative PCR was conducted to validate the results by quantifying the abundance of the AOB and total bacteria, and similar results were obtained. Overall, the results presented in this study may provide new insights into our understanding of key microorganisms and the entire community of tannery wastewater and contribute to improving the nitrogen removal efficiency.

Formation of Ethyl Carbamate in Goji wines: Effect of Goji Fruit Composition

Qiang Xia,Meican Niu,Chong-De Wu,Rongqing Zhou 한국식품과학회 2016 Food Science and Biotechnology Vol.25 No.3

Ethyl carbamate (EC) is a multisite carcinogen widely occurring in alcoholic beverages. In this investigation, solid-phase extraction combined with gas chromatography mass spectrometry was employed to determine EC contents during the fermentation and storage processes, and the effects of Goji varieties on its formation were also examined. The results indicated that natural and potential EC contents were significantly affected by the varied composition of Goji fruits. The analysis of chemical properties showed differences in hundred-grain weight, water contents, amino acids, and nitrogen-tocarbon ratio for Goji berries. Citrulline was completely degraded although it is routinely considered as a non-preferred nitrogen for yeasts. Due to compositional differences, Goji wines accumulated distinct urea levels that positively correlated with the potential EC contents. Furthermore, the temperature in both the production processes highly influenced EC formation. These results contribute to a more comprehensive understanding of EC formation, and in turn, controlling EC in the Goji wine matrix.

Characterizing the interaction relationship of the microbial communities between Zaopei and pit mud disturbing by Daqu

Suqi Chen,Jun Huang,Hui Qin,Rongqing Zhou,Yan Yang,Chuanfeng Qiu,Suyi Zhang 한국식품과학회 2021 Food Science and Biotechnology Vol.30 No.10

The differences of interaction between interphasemicrobial communities were evaluated caused bytwo kinds of Daqu, including conventional Daqu (CDQ)and fortified Daqu (FDQ). The community diversity,functional genera and metabolites in pit mud (PM) andZaopei (ZP) were investigated by polyphasic detectingapproaches. FDQ evolved the core microbial communityfitting Baijiu brewing faster than CDQ. Compared withCPM, the abundance of Aspergillus, Hyphopichia, andPenicillium in FPM were 1.54, 14.75, and 1.68 times, whilethat of Lactobacillus, Bacillus, Methanobrevibacter, andMethanosaeta were 2.13, 1.85, 6.35, and 3.36 times,respectively. Furthermore, the content of key flavor componentswas increased in ZP using FDQ. These resultssuggested the interaction between interphase microbialcommunities in various phases of Baijiu fermentationniches was significant influenced by Daqu. It can not onlyenhance the key volatiles in ZP but also evolve the communityto fit Baijiu fermentation by introducing functionalgenera to Daqu.

Preparation and Photoelectric Properties of Silver Nanowire/ZnO Thin Film Ultraviolet Detector

Zhenfeng Li,Wei Xiao,Hongzhi Zhou,Zhiyuan Shi,Rongqing Li,Jia Zhang,Yang Li,Peng He,Shuye Y. Zhang 대한금속·재료학회 2023 ELECTRONIC MATERIALS LETTERS Vol.19 No.5

Ultraviolet (UV) detectors have important applications in many fi elds. ZnO is an excellent semiconductor material for the preparation of UV detectors because of its large direct gap in forbidden bandwidth, its intrinsic response band in the UV region, and its high exciton binding energy. In this paper, high-performance ZnO thin fi lms with the optically advantageous nonpolar structure were prepared by using an atomic layer deposition, and the dominant crystal plane gradually changes from the amorphous phase to the (100) crystal plane. The conventional photoconductor structure ZnO UV detector was enhanced by the surface plasmon exciton eff ect of Ag nanostructure. When the operating voltage is 5 V and the response light is 350 nm, there is a maximum optical responsiveness of up to 131 A/W. The UV/visible rejection ratio can reach 1824 times. When the ZnO thin fi lm deposition thickness is 400 deposition cycles and about 72 nm, the ZnO thin fi lm UV detector obtains the highest responsiveness (5 V, 365 nm) of 365 A/W. Comparing the photovoltaic performance of the ZnO thin-fi lm detector with the enhanced ZnO thin-fi lm detector and its optimal response wavelength, it is found that the enhanced ZnO thin-fi lm detector increased the photoresponse value by about 100 times. The optimal response wavelength in the UV region is blueshifted, and the UV-visible rejection ratio and optical response rate are signifi cantly improved.

Characterization of Interphase Microbial Community in Luzhou-Flavored Liquor Manufacturing Pits of Various Ages by Polyphasic Detection Methods

( Hui Li ),( Jun Huang ),( Xinping Liu ),( Rongqing Zhou ),( Xiaofei Ding ),( Qianyin Xiang ),( Liqiang Zhang ),( Chongde Wu ) 한국미생물 · 생명공학회 2017 Journal of microbiology and biotechnology Vol.27 No.1

It is vital to understand the changing characteristics of interphase microbial communities and interspecies synergism during the fermentation of Chinese liquors. In this study, microbial communities in the three indispensable phases (pit mud, zaopei, and huangshui) of Luzhou-flavored liquor manufacturing pits and their shifts during cellars use were first investigated by polyphasic culture-independent approaches. The archaeal and eubacterial communities in the three phases were quantitatively assessed by combined phospholipid ether lipids/ phospholipid fatty acid analysis and fluorescence in situ hybridization. In addition, qualitative information regarding the microbial community was analyzed by PCR-denaturing gradient gel electrophoresis. Results suggested that the interphase microbial community profiles were quite different, and the proportions of specific microbial groups evolved gradually. Anaerobic bacteria and gram-positive bacteria were dominant and their numbers were higher in pit mud (10⁹ cells/g) than in huangshui (10⁷ cells/ml) and zaopei (10⁷cells/g). Hydrogenotrophic methanogenic archaea were the dominant archaea, and their proportions were virtually unchanged in pit mud (around 65%), whereas they first increased and then decreased in zaopei (59%-82%-47%) and increased with pit age in huangshui (82%-92%). Interactions between microbial communities, especially between eubacteria and methanogens, played a key role in the formation of favorable niches for liquor fermentation. Furthermore, daqu (an essential saccharifying and fermentative agent) and metabolic regulation parameters greatly affected the microbial community.

Effect of Exogenous Proline on Metabolic Response of Tetragenococcus halophilus under Salt Stress

( Guiqiang He ),( Chongde Wu ),( Jun Huang ),( Rongqing Zhou ) 한국미생물생명공학회(구 한국산업미생물학회) 2017 Journal of microbiology and biotechnology Vol.27 No.9

This study investigated the effect of proline addition on the salt tolerance of Tetragenococcus halophilus. Salt stress led to the accumulation of intracellular proline in T. halophilus. When 0.5 g/l proline was added to hyperhaline medium, the biomass increased 34.6% (12% NaCl) and 27.7% (18% NaCl) compared with the control (without proline addition), respectively. A metabolomic approach was employed to reveal the cellular metabolic responses and protective mechanisms of proline upon salt stress. The results showed that both the cellular membrane fatty acid composition and metabolite profiling responded by increasing unsaturated and cyclopropane fatty acid proportions, as well as accumulating some specific intracellular metabolites (environmental stress protector). Higher contents of intermediates involved in glycolysis, the tricarboxylic acid cycle, and the pentose phosphate pathway were observed in the cells supplemented with proline. In addition, addition of proline resulted in increased concentrations of many organic osmolytes, including glutamate, alanine, citrulline, N-acetyl-tryptophan, and mannitol, which may be beneficial for osmotic homeostasis. Taken together, results in this study suggested that proline plays a protective role in improving the salt tolerance of T. halophilus by regulating the related metabolic pathways.

Metabolic Response of Tetragenococcus halophilus under Salt Stress

Guiqiang He,Chongde Wu,Jun Huang,Rongqing Zhou 한국생물공학회 2017 Biotechnology and Bioprocess Engineering Vol.22 No.4

In this study, the effect of salt stress on metabolic response of Tetragenecoccus halophilus was investigated, and the metabolic alternations were analyzed using liquid chromatography-mass spectrometry according to the metabolomics approach. A total of 81 intracellular metabolites were identified, and significant differences were observed in the levels of metabolites mainly participating in central carbon metabolism, fatty acid metabolism, and amino acid metabolism. Analysis of the membrane fatty acid distribution showed that higher proportions of unsaturated fatty acid were observed in salt-treated cells. Additionally, salt-stressed cells exhibited higher amounts of compatible solutes including proline, glycine, citrulline, and N-acetyltyrptophan, and lower amounts of branched-chain amino acids. Interestingly, higher amounts of indole, salicylic acid, and coronatine, which are regarded as signaling molecule and suggested to combat osmotic stress, were detected in salt-shocked cells compared with the untreated cells. Taken together, these results suggested that increased unsaturated membrane fatty acids, accumulation of compatible solutes, and up-regulation of signaling molecule may be potential mechanisms employed by T. halophilus during salt stress.

Zygosaccharomyces rouxii Combats Salt Stress by Maintaining Cell Membrane Structure and Functionality

Dingkang Wang,Min Zhang,Jun Huang,Rongqing Zhou,Yao Jin,Chongde Wu 한국미생물·생명공학회 2020 Journal of microbiology and biotechnology Vol.30 No.1

Zygosaccharomyces rouxii is an important yeast that is required in the food fermentation process due to its high salt tolerance. In this study, the responses and resistance strategies of Z. rouxii against salt stress were investigated by performing physiological analysis at membrane level. The results showed that under salt stress, cell integrity was destroyed, and the cell wall was ruptured, which was accompanied by intracellular substance spillover. With an increase of salt concentrations, intracellular Na+ content increased slightly, whereas intracellular K+ content decreased significantly, which caused the increase of the intracellular Na+/K+ ratio. In addition, in response to salt stress, the activity of Na+/K+-ATPase increased from 0.54 to 2.14 μmol/mg protein, and the ergosterol content increased to 2.42-fold to maintain membrane stability. Analysis of cell membrane fluidity and fatty acid composition showed that cell membrane fluidity decreased and unsaturated fatty acid proportions increased, leading to a 101.21% rise in the unsaturated/saturated fatty acid ratio. The results presented in this study offer guidance in understanding the salt tolerance mechanism of Z. rouxii, and in developing new strategies to increase the industrial utilization of this species under salt stress.

Design, Optimization and Verification of 16S rRNA Oligonucleotide Probes of Fluorescence in-situ Hybridization for Targeting Clostridium spp. and Clostridium kluyveri

( Lintao Hu ),( Jun Huang ),( Hui Li ),( Yao Jin ),( Chongde Wu ),( Rongqing Zhou ) 한국미생물생명공학회(구 한국산업미생물학회) 2018 Journal of microbiology and biotechnology Vol.28 No.11

Fluorescence in-situ hybridization (FISH) is a common and popular method used to investigate microbial communities in natural and engineered environments. In this study, two specific 16S rRNA-targeted oligonucleotide probes, CLZ and KCLZ, were designed and verified to quantify the genus Clostridium and the species Clostridium kluyveri. The optimal concentration of hybridization buffer solution for both probes was 30% (w/v). The specificity of the designed probes was high due to the use of pellets from pure reference strains. Feasibility was tested using samples of Chinese liquor from the famed Luzhou manufacturing cellar. The effectiveness of detecting target cells appears to vary widely in different environments. In pit mud, the detection effectiveness of the target cell by probes CLZ and KCLZ was 49.11% and 32.14%, respectively. Quantitative analysis by FISH technique of microbes in pit mud and fermented grains showed consistency with the results detected by qPCR and PCR-DGGE techniques, which showed that the probes CLZ and KCLZ were suitable to analyze the biomass of Clostridium spp. and C. kluyveri during liquor fermentation. Therefore, this study provides a method for quantitative analysis of Clostridium spp. and C. kluyveri and monitoring their community dynamics in microecosystems.