Purification of AS-CMP effluent by combined photosynthetic bacteria and coagulation treatment

The effluent from the pulping of E. urophylla by alkali sodium sulfite chemi mechanical process(AS-CMP) was characterized for its biodegradability by photosynthetic bacteria (PSB). Chemical coagulation post treatment of biotreated wastewater was also studied. One month continuous treatment in the laboratory indicated that the COD Cr , BOD 5 and SS removals in biotreatment stages reached 56%, 83% and 89% respectively, and the CH 2Cl 2 extractives decreased from 10.7 mg/L to 7.7 mg/L. In chemical coagulation post treatment stage, the effects of process conditions, such as coagulant dosage, pH value and the coordinated coagulation flocculation treatment of three kinds of coagulants on coagulation effectiveness were discussed. The optimum operating conditions were given.

Annual change of the number of anaerobic sulf ite reducing bacteria in sediment of the Daya Bay

The surface sediment samples were collected month by month at nine stations in the Daya Bay from January to December 1987, and the number of anaerobic sulfite reducing bacteria and their spores and the regularity of seasonal change were determined. The effect of environmental factors, water temperature and the resoluble oxygen concentration in the bottom of seawater on the number of them were discussed. The results show that the number of anaerobic su|fite reducing bacteria were low in sediment of the Daya Bay, indicating that the hay was less contaminated.

Study on the synthesis and antimicrobial activity of novel cationic porphyrins

A novel series of quaternary ammonium cationic derivatives based on tetrapyridyl-porphyrin was synthesized. All the compounds were evaluated for their in vitro antibacterial activities against S. aureus, E. coli and P. aeruginosa, and antifungal activities against C. albicans, where microorganisms were exposed and unexposed to the irradiation. The results revealed that some of these compounds, especially, 3a and 4a displayed satisfactory antibacterial activity against Gram-positive bacteria S. aureus and moderate antifungal activity against C. albicans. Unfortunately, Gram-negative bacteria P aeruginasa was resistant to all compounds. The antimicrobial activity was found to be sensitive to the functional groups attached on the aromatic ring and the complex metal in the porphyrin ring, and decreased with the increase of electron-withdrawing capability of the functional groups. These preliminary results suggested that the remarkable antibacterial efficiency against S. aureus makes these substances promising antimicrobial agents.

Fractal characteristics of filamentous bacteria in activated sludge and its significance

On the basis of fractal theory, the fractal characteristics of filamentous bacteria in activated sludge are studied by image dissector system. The results show that the spatial distribution structure of filamentous bacteria in activated sludge has high self similarity in statistics and the filamentous bacteria have clear phenomenon of fractal growth. The critical fractal dimension values of filamentous bacteria bulking such as Eikelboom 021N, Eikelboom 1701, Sphaerotilus natans and Eikelboom 0041 are determined initially. The fractal dimensions can be taken as a parameter to describe filamentous bacteria of activated sludge quantitatively and bring to light the disorder in appearance and the rule in inherence of filamentous bacteria system.

Evaluation of the Method Based on Restriction Fragment Length Polymorphism Analysis as Simple Analysis Method of Lactic Acid Bacteria in Foods

Lactic acid bacteria have not only been used to produce various kinds of fermented food, but also used as probiotic products. As lactic acid bacterial group was consisted from diverse genera, a simple inspection method by which numbers and contained microorganisms could be automatically analyzed without any preliminary information was required to use them more effectively. In this manuscript, lactic acid bacterial groups in commercial products of kimuchi, komekouji-miso, and yoghurt were identified and enumerated by our newly developed method [1]-[3], to evaluate whether the method could be used as an inspection method of various food samples. In kimuchi, numerically dominant bacteria were Lactobacillus sakei, and L. casei (1.4 × 104 MPN g-1) and Leuconostoc spp. (l.4 × 104 MPN). In kouji-miso, numerically dominant bacteria was Bacillus spp. (3 × 103 MPN), which mainly included B. subtilis group and B. cereus group. Lactic acid bacteria such as Lactobacillus spp., or Lactococcus spp., included in the komekouji-miso, could be enumerated after 3 days incubation (1.24 × 104 MPN), but not detected after 7 days incubation. In yoghurt A and C, Lactococcus lactis was detected as numerically dominant lactic acid bacteria (3.0 × 105 MPN). In yoghurt B, Lactobacillus spp., or Lactococcus spp., was detected not only by a culturebased method but also by an unculture-based method, although there was a difference between the both estimated numbers. The present results suggested that the method might become useful as a simple inspection method of food microorganisms, because time and labor of the analysis could be reduced by using an unculture-based method and MCE-202 MultiNA. In this study, Bifidobacteriium spp. was not detected in B and C yoghurt, in spite of indicating their existence, and numbers of lactic acid bacteria were lower than the level of the daily product regulation, because 16S rDNA of Bifidobacteriium spp. might not be amplified by the used PCR condition. The PCR condition must be changed so as to amplify Bifidobacterium spp., before the method will be used as an inspection method for lactic acid bacteria.

Dynamics of Phenol Degrading-Iron Reducing Bacteria in Intensive Rice Cropping System

Field and greenhouse experiments were conducted to investigate the effects of cropping season, nitrogen fertilizer input and aerated fallow on the dynamics of phenol degradihg-iron reducing bacteria (PD-IRB) in tropical irrigated rice (Oryza sativa L.) systems. The PD-IRB population density was monitored at different stages of rice growth in two cropping seasons (dry and early wet) in a continuous annual triple rice cropping system under irrigated condition. In this system, the high nitrogen input (195 and 135 kg N ha-1 in dry and wet seasons, respectively) plots and control plots receiving no N fertilizer were compared to investigate the effect of nitrogen rate on population size. The phenol degrading-iron reducing bacteria (PD-IRB) were abundant in soils under cropping systems of tropical irrigated rice. However, density of the bacterial populations varied with rice growth stages. Cropping seasons, rhizosphere, and aerated fallow could affect the dynamics of PD-IRB. In the field trial, viable counts of PD-IRB in the topsoil layer (15 cm) ranged between 102 and 108 cells per gram of dry soil, A steep increase in viable counts during the second half of the cropping season suggested that the population density of PD-IRB increased at advanced crop-growth stages. Population growth of PD-IRB was accelerated during the dry season compared to the wet season. In the greenhouse experiment, the adjacent aerated fallow revealed 1-2 orders of magnitude higher in most probable number (MPN) of PD-IRB than the wet fallow treated plots. As a prominent group Of Fe reducing bacteria, PD-IRB predominated in the rhizosphere of rice, since maximum MPN of PD-IRB (2.62×108 g-1 soil) was found in rhizosphere soil. Mineral N fertilizer rates showed no significant effect on PD-IRB population density.

Evaluation of the relationship between two different methods for enumeration fecal indicator bacteria: Colony-forming unit and most probable number

Most probable number （MPN） and colony-forming unit （CFU） estimates of fecal indicator bacteria （FIB） concentration are common measures of water quality in aquatic environments. Thus, FIB intensively monitored in Yeongsan Watershed in an attempt to compare two different methods and to develop a statistical model to convert from CFU to MPN estimates or vice versa. As a result, the significant difference was found in the MPN and CFU estimates. The enumerated Escherichia coli concentrations in MPN are greater than those in CFU, except for the measurement in winter. Especially in fall, E. coli concentrations in MPN are one order of magnitude greater than that in CFU. Contrarily, enterococci bacteria in MPN are lower than those in CFU. However, in general, a strongly positive relationship are found between MPN and CFU estimates. Therefore, the statistical models were developed, and showed the reasonable converting FIB concentrations from CFU estimates to MPN estimates. We expect this study will provide preliminary information towards future research on whether different analysis methods may result in different water quality standard violation frequencies for the same water sample.

不同pH对瘤胃细菌数量和菌群结构的影响

【目的】试验旨在研究瘤胃不同pH下瘤胃酸中毒相关细菌数量和瘤胃细菌菌群结构的变化。【方法】选取5头干奶期荷斯坦奶牛作为瘤胃液供体,调节瘤胃液pH分别为6.5、5.8、5.5、5.2和5.0。培养3 h后,采用qPCR技术测定瘤胃酸中毒相关细菌数量,采用16S rDNA高通量测序技术研究瘤胃细菌菌群结构的变化。【结果】(1)瘤胃pH对白色瘤胃球菌(Ruminococcus ablus)的相对数量没有影响(P>0.05),但显著影响了乳酸产生菌和乳酸利用菌的相对数量(P<0.05)。其中牛链球菌(Streptococcus bovis)相对数量随着pH的下降而升高,在pH 5.0处极显著高于其余各组(P<0.05);埃氏巨型球菌(Megasphaeraelsdenii)、反刍兽新月单胞菌(Selenomonas ruminantium)及乳酸杆菌(Lactobacillus species)随pH下降呈现先升高后下降的趋势,pH分别在pH 5.5或pH 5.2处达到最大值(P<0.05);(2)α多样性结果显示,瘤胃细菌数量和菌群的丰富度及多样性呈现随瘤胃pH下降先升高后下降的趋势,其中Chao1指数在pH 5.5处,Observed species和Shannon指数在pH 5.2处最高(P<0.05)。β多样性结果显示pH 6.5、pH 5.8处理组与pH 5.2、pH 5.0处理组的菌群构成有明显差异,pH 5.5处理组样本与其他4组样本距离较远,其菌群构成与其他4组具有差异;(3)在菌群组成上,瘤胃内主要菌门和属的菌群丰度随pH的降低也多有改变。pH 5.2、pH 5.0处理组和pH 6.5、pH 5.8处理组菌群结构有显著差异(P<0.05)。pH 6.5组与pH 5.8组的菌群组成差异不大(P>0.05),仅普雷沃氏菌科UGG-003菌属(Prevotellaceae UCG-003)和琥珀酸弧菌科UGG 002菌属(Succinivibrionaceae UCG 002)有差异;pH 5.0处理组与pH 5.2处理组的菌群组成较一致(P>0.05),仅在螺旋体门(Spirochaetota)、放线菌门(Actinobacteriota)、瘤胃菌属(Ruminococcus)和解琥珀菌属(Succiniclasticum)有差异(P<0.05);而pH 5.5处理组的菌群构成与其他4组有显著差异(P<0.05)。【结论】环境pH改变是瘤胃细菌遭受的一种严重干扰,会引起瘤胃内乳酸产生菌和乳酸利用菌的相对数量显著改变。瘤胃细菌数量、菌群丰富度和多样性也随瘤胃pH的下降表现出先升高后降低的趋势,其变化规律符合生态学中的“中度干扰假说”。

湖北省2个规模化蛋鸡养殖场环境细菌监测分析

为了解蛋鸡养殖场环境中病原菌流行情况,试验采集湖北省不同地区2个规模化蛋鸡养殖场不同位置的空气、水线和饲料样品进行病原菌检测,并采用16S rDNA测序分析样品中的优势病原菌。结果显示:饲料样品中细菌总数符合《GB 13078—2017饲料卫生标准》,而鸡舍风机附近空气及水线中细菌总数均较高;空气中优势病原菌是芽孢杆菌和葡萄球菌,饲料和水线优势菌为芽孢杆菌。结果表明,规模化蛋鸡养殖场饲料中的芽孢杆菌易污染水线和空气,风机附近是细菌污染重点区域,应定期消毒。

Human activity over natural inputs determines the bacterial community in an ice core from the Muztag ata glacier

Ice core provides a valuable vertical timeline of past climates and anthropogenic activities.Environmental proxies have been widely used in these studies,but there are few biological indicators available.To address this gap,we investigated the bacterial community from a 74 m ice core of Muztag ata glacier on the Tibetan Plateau to link biological indicators with past climate and anthropogenic activities.By analyzing the portion of the ice core with environmental proxies available(corresponding to 1907 to 1991),we observed an increase in bacterial richness throughout the ice core,which was associated with higher NH_(4)^(+),an indicator of agricultural development.The bacterial community was jointly determined by human activity,natural input,and air temperature,with a strong human influence after the 1950s.Furthermore,the relative abundance of animal gut-associated bacteria,including Aerococcaceae,Nocardiaceae,Muribaculaceae,and Lachnospiraceae,was associated with livestock number changes in the Central Asian region.Together with other bacterial lineages,they jointly explained 59.8%of the livestock number changes.This study provides quantitative evidence of the associations between bacterial indicators and past climate and human activities,highlighting the potential of using bacterial proxies for ice core studies.

发酵乳和乳饮料中乳酸菌活菌数ATP检测方法的开发与应用

乳酸菌活菌数作为发酵乳和乳酸菌饮料的产品质量属性,同时作为国家风险抽检项目,目前的检测方法存在操作烦琐、检测周期长、结果滞后等缺点,无法满足企业产品卖点宣称及质量控制,故针对发酵乳和乳饮料中乳酸菌活菌数的快速检测方法进行开发、研究,旨在提高检测结果准确性、稳定性及缩短检测周期。每种微生物中的腺嘌呤核苷三磷酸(Adenosine Triphosphate,ATP)含量都是基本恒定的,而ATP的相对发光单位(Relative Luminescence Unit,RLU)与ATP含量呈线性关系,通过建立产品中乳酸菌数量与ATP的RLU(相对发光单位)的相关关系开发乳酸菌快速检测方法。通过试验证实该方法与国家标准检测方法具有一致性,能够快速、准确地检测产品中乳酸菌数活菌数,为生产销售流通中的质量监测提供一种快捷方便的方法。

平板计数法检测化妆品中需氧细菌总数的不确定度评估

文章将不确定度原理引入平板计数中,以测量需氧细菌总数检测过程中平皿计数法的检测误差。检测方法参照USP 2023<61>中的“非无菌产品微生物限度检查”,采用微生物计数法定量检测化妆品中的需氧细菌总数,并参照JJF1059.1-2012《测量不确定度评定与表示》中的要求,用需氧细菌总数对数值表示,通过评定需氧细菌总数检测中平皿计数法测量的不确定度,探讨平皿计数的检测误差[1]。结果表明,平皿法检测需氧菌总数的测量误差主要由A类评定的不确定度所致,而B类评定不确定度造成的误差可以忽略不计,因而据此得出可以扩展不确定度。研究所得的通过对需氧细菌总数检测中平皿计数结果的测量进行不确定度评定,可用于评估平皿计数法的检测误差[2]。

不同土壤菌配置对赣南山区土壤酶活性及微生物数量的影响

随着我国经济建设的不断发展,工程施工后期的迹地恢复是保护环境、维护生态平衡的重要环节。为解决这一问题,采用土壤菌配置加客土喷播技术进行迹地恢复,将不同的土壤菌配置(DL1+DL2、DL1+DL3、DL2+DL3、DL1+DL2+DL3)加入喷播基质中并通过喷播的方式铺设到赣南山区边坡。针对赣南山区边坡后期迹地恢复问题,提出最优的土壤菌配置模式。结果表明,土壤菌的施用,促进土壤微生物活动,加速土壤中的生化反应,加入土壤菌能显著提高赣南山区边坡土壤的过氧化氢酶活性、蔗糖酶活性、中性磷酸酶活性和纤维素酶活性,能显著提高土壤中真菌、细菌、放线菌以及微生物的总数量,其中土壤菌DL1+DL2配置模式下对提高赣南山区土壤酶活性以及微生物数量效果最明显。

五台山不同海拔土壤可培养细菌数量特征研究

为探究山西境内不同海拔梯度下土壤可培养细菌数量特征及其变化趋势,选择海拔梯度大、垂直特征明显的五台山作为研究区域,以不同海拔(1452、1646、1870、2068、2284、2522和2750 m)、不同深度(0~10 cm、20~30 cm)土壤为研究对象,采用稀释平板法分析不同海拔、不同土壤深度可培养细菌数量分布特征。结果表明:五台山土壤可培养细菌数量介于4.30×10^(7)~18.55×10^(7)CFU·g^(-1)之间,平均值为10.80×10^(7)CFU·g^(-1);可培养细菌数量随着海拔高度的上升呈显著下降趋势(P<0.05);除1646 m样点外,其他6个样点0~10 cm与20~30 cm土壤可培养细菌数量均存在显著差异(P<0.05);土壤可培养细菌数量与含水量呈极显著负相关(P<0.01)。研究区域土壤可培养细菌数量受海拔高度、土壤深度及含水量显著影响。

能力验证非无菌药品微生物检查的不确定度评定

目的:评定能力验证非无菌药品微生物检查的不确定度。方法:根据《中华人民共和国药典(2020年版)》、JJF 1059.1-2012《测量不确定度评定与表示》、SN/T 4091-2015《食品微生物学测量不确定度评估指南》,对不确定度来源进行分析与评定。结果:样品236需氧菌总数1.7×10^(3) cfu/mL,扩展不确定度U_(236)=0.0666log10(cfu/mL),反对数取值区间(1460,1980)cfu/mL;样品316霉菌和酵母菌总数9.5×10^(2) cfu/mL,扩展不确定度U_(316)=0.0744log10(cfu/mL),反对数取值区间(800,1120)cfu/mL,k=2。

Antibiotic-Resistant Bacterial Group in Field Soil Evaluated by a Newly Developed Method Based on Restriction Fragment Length Polymorphism Analysis

Spreading of antibiotic resistant bacteria into environment is becoming a major public health problem, implicating affair of the indirect transmission of antibiotic resistant bacteria to human through drinking water, or vegetables, or daily products. Until now, the risk of nosocomial infection of antibiotic resistant bacteria has mainly been evaluated using clinical isolates by phenotypic method. To evaluate a risk of community-acquired infection of antibiotic resistant bacteria, a new method has been developed based on PCR-RFLP without isolation. By comparing restriction fragment lengths of the 16S rDNA gene from bacterial mixture grown under antibiotic treatment to those simulated from the DNA sequence, bacterial taxonomies were elucidated using the method of Okuda and Watanabe [1] [2]. In this study, taxonomies of polymyxin B resistant bacteria group in field soils, paddy field with organic manure and upland field without organic manure were estimated without isolation. In the both field soils, the major bacteria grown under the antibiotic were B. cereus group, which had natural resistance to this antibiotic. In field applied with organic manure, Prevotella spp., and the other Cytophagales, which were suggested to be of feces origin and to acquire resistance to the antibiotic, were detected. When numbers of each bacterial group were roughly estimated by the most probable number method, B. cereus group was enumerated to be 3.30 × 106 MPN/g dry soil in paddy field soil and 1.32 × 106 MPN/g dry soil in upland filed. Prevotella spp. and the other Cytophagales in paddy field were enumerated to be 1.31 × 106 MPN, and 1.07 × 106 MPN·g-1 dry soil.

Five-year analysis of isolated pathogens and antibiotic resistance of ocular infections from two large tertiary comprehensive hospitals in east China

AIM:To analyze the spectrum of isolated pathogens and antibiotic resistance for ocular infections within 5y at two tertiary hospitals in east China.METHODS:Ocular specimen data were collected from January 2019 to October 2023.The pathogen spectrum and positive culture rate for different infection location,such as keratitis,endophthalmitis,and periocular infections,along with antibiotic resistance were analyzed.RESULTS:We included 2727 specimens,including 827(30.33%)positive cultures.A total of 871 strains were isolated,530(60.85%)bacterial and 341(39.15%)fungal strains were isolated.Gram-positive cocci(GPC)were the most common ocular pathogens.The most common bacterial isolates were Staphylococcus epidermidis(25.03%),Staphylococcus aureus(7.46%),Streptococcus pneumoniae(4.59%),Corynebacterium macginleyi(3.44%),and Pseudomonas aeruginosa(3.33%).The most common fungal genera were Fusarium spp.(12.74%),Aspergillus spp.(6.54%),and Scedosporium spp.(5.74%).Staphylococcus epidermidis strains showed more than 50%resistance to fluoroquinolones.Streptococcus pneumoniae and Corynebacterium macginleyi showed more than 90%resistance to erythromycin.The percentage of bacteria showing multidrug resistance(MDR)significantly decreased(χ^(2)=17.44,P=0.002).CONCLUSION:GPC are the most common ocular pathogens.Corynebacterium macginleyi,as the fourth common bacterium,may currently be the local microbiological feature of east China.Fusarium spp.is the most common fungus.More than 50%of the GPC are resistant to fluoroquinolones,penicillins,and macrolides.However,the proportion of MDR strains has been reduced over time.

Use of Low Radioactive Rare-earth Waste for Sewage Treatment

Low radioactive rare earth waste (containing 232 Th,specific activity 5 000 8 000 Bq·kg -1 ) were diluted 20 times by cement,sand and carbide ash and were made into special cement.The radioactivity of this special cement complied with the healthy protect standard for radioactive materials (GB6566 86).Test results showed that this special cement could lower COD,the degradation rate increased as the time went on.In acidic medium,this special cement could remove E Coli effectively.Applying aeration and adding lumps of cement,the degradation of COD versus time complied with Logistic model through fitting by computer.The two “S” curves indicated that aeration and adding lumps of cement had synergistic action on sewage treatment.

A New Evaluation Method for Antibiotic-Resistant Bacterial Groups in Environment

In the present manuscript it was presented whether spreading of antibiotic resistant bacterial groups in environment could be monitored by our newly developed method by enumerating antibiotic resistant bacterial groups in various biological wastes and composts. Although the numbers were not so high, diverse kinds of colistin resistant bacteria (25 mg·L-1) were included in row cattle feces (1.78 × 104 MPN g-1) and cattle feces manure (>3.84 × 104 MPN g-1). Compost originated from leftover food (>44.8 × 104 MPN g-1) and shochu lee (>320 × 104 MPN g-1) included higher numbers of chlortetracycline resistant Pseudomonas sp., (25 mg·L-1), and row cattle feces included higher numbers of chlortetracycline resistant Enterobacteriacea (15.7 × 104 MPN g-1), which mostly consisted from Pantoea sp. or Xenorhobdus doucetiae. Numbers of multi drug resistant bacteria, resistant to 25 mg·L-1 of ciprofloxacin, streptomycin, chloramphenicol, and ampicillin, were the highest in row cattle feces (>143.6 × 104 MPN g-1), followed by cattle feces manure (4.19 × 104 MPN g-1), and shochu lee (0.36 × 104 MPN g-1), which included diverse kinds of bacterial group. The present results indicated that higher numbers of multi drug resistant bacteria were typically found in row cattle feces, and the method was found suitable to enumerate and identify them. These results suggested that the method might become their environmental risk evaluation method.

不同温度和时间下散养鸡鸡蛋感官、微生物以及氨基酸变化分析

为研究散养鸡鸡蛋在不同温度和时间下感官指标、微生物数目以及氨基酸成分的变化,试验选取信阳市不同散养鸡场随机采集同一日龄、大小均匀、品质良好的鸡蛋200枚进行试验。将200枚鸡蛋随机分为2组,每组100枚,分别放置在4℃冰箱和25℃恒温箱两种条件下储存,每隔7 d取样,测定所取样品的蛋重、蛋黄指数、蛋清pH、菌落总数、大肠杆菌和沙门氏菌的数目,同时每隔14 d取样分析氨基酸成分的变化。结果表明:4℃和25℃条件下贮藏的鸡蛋其蛋重、蛋黄指数会随储存时间的延长而降低,4℃条件下,28 d时蛋重较1 d时下降了8.09%,但差异不显著(P>0.05),35 d时蛋黄指数较1 d时下降了14.89%,差异显著(P<0.05),25℃条件,28 d时蛋重最低和1 d相比降低了14.86%,差异显著(P<0.05);14 d时蛋黄指数较1 d降低了31.91%,在21 d时蛋清pH较1 d时增加了19.50%,差异显著(P<0.05)。鸡蛋内部微生物的数量也会随储存时间的延长而明显增加,4℃条件下,35 d时蛋黄中沙门氏菌、蛋清中的大肠杆菌和沙门氏菌数目分别是28 d的53.37倍、5.27倍和3.44倍(P<0.05)。25℃条件下,28 d时蛋黄中菌落总数、蛋清中菌落总数、蛋黄中大肠杆菌和沙门氏菌数目、蛋清中大肠杆菌和沙门氏菌数目分别是21 d的19.71倍、17.65倍、6.43倍、3.70倍、52.67倍和17.15倍;氨基酸总量(TAA)、必需氨基酸(EAA)含量、非必需氨基酸(NEAA)含量均有所降低,4℃下储存的鸡蛋各氨基酸含量无显著变化,25℃下的鸡蛋在储藏过程中其苯丙氨酸(Phe)、蛋氨酸(Met)、赖氨酸(Lys)含量出现显著差异(P<0.05)。综上,散养鸡鸡蛋感官品质、微生物数量以及氨基酸含量与储存时间呈正相关,与储存温度呈负相关,其4℃条件下鸡蛋品质下降程度较小。