Correlation of Aflatoxin Contamination in Peanuts with Rhizosphere Microorganisms and Its Comprehensive Control

Aflatoxin contamination is an important hazard factor affecting the quality safety and food safety of peanut production, which seriously threatens people's health and safety. In this paper, the background and harmful causes of aflatoxin contamination were analyzed in detail, with attention focusing on its control measures, which has certain guiding significance for the comprehensive control of aflatoxin contamination.

Influencing Factors and Biological Control of Aflatoxin Contamination in Peanuts

Peanut is an important economic crop and oil crop in China.It is vulnerable to infection by Aspergillus flavus during production,storage,transportation and processing,causing aflatoxin(AFT)contamination.This paper introduced the status and characteristics of AFT contamination in China,analyzed the infection pathways and influencing factors of A.flavus,and discussed the prevention and control technology of AFT contamination in peanuts from the view of the use of beneficial microorganisms.

Controlled-release fertilizer(CRF): A green fertilizer for controlling non-point contamination in agriculture

Fertilizers contribute greatly to high yields but also result in environmental non-point contamination, including the emission of greenhouse gas(N 2O) and eutrophication of water bodies. How to solve this problem has become a serious challenge, especially for China as its high ecological pressure. Controlled-release fertilizer(CRF) has been developed to minimize the contamination while keeping high yield and has become a green fertilizer for agriculture. Several CRFs made with special coating technology were used for testing the fertilizer effects in yield and environment through pot experiment and field trial. The result indicated that the CRFs had higher N use efficiency, thus reducing N loss through leaching and volatilization while keeping higher yields. Comparing with imported standard CRFs, the test on CRFs showed similar fertilizer effect but with much lower cost. CRFs application is becoming a new approach for minimizing non-point contamination in agriculture.

Preliminary Study on Biological Control of Mycotoxin Contamination in Agricultural Products and Its Mechanism

Aflatoxin is the most powerful carcinogen and highly toxic mycotoxin known in nature. It can cause serious toxin pollution to agricultural products, foods and fodders, and is extremely harmful to human and animal health. For aflatoxin pollution, the emphasis is on the control of source, and biological control is favored by scientists because of its advantages of environmental protection and ecological safety. According to the morphology, color and appearance of microbial colonies isolated from maize kernels, 300 bacterial strains were obtained from main maize-producing areas including Tangshan City, Handan City, Shijiazhuang City and Cangzhou City. Two biocontrol bacterial strains(B120 and B65) having a strong control effect on aflatoxins were screened. After identification by molecular biology and physical and chemical properties, the two biocontrol bacterial strains were identified as Bacillus amyloliquefaciens. Their effects on spore germination, mycelial growth and toxin degradation of Aspergillus flavus were investigated. The results showed that strains B120 and B65 could significantly inhibit the spore germination and mycelial growth of A. flavus and reduce aflatoxin production. This study provides a new way to prevent and control the pollution control of aflatoxins in agricultural products.

Analysis of Microbial Contamination Factors and Critical Control Points in the Process of Hog Slaughter and Production

In order to provide a reference for the further study of microbial contamination in the pork production process. Microbial contamination of pigs came from three slaughterhouses were detected, and critical control points in the progress of hog slaughter and processing were analyzed. The results showed that microbial con- taminatian existed in the entire slaughter and processing progress, including shower and assassination bloodletting, separation of the internal organs, chopping boards, workshop environment, personal hygiene of the operators, etc. , which should be paid more attention to. The results indicated that reasonable protection measures should be carried out, disinfection awareness of the operators should be improved, and regular disinfection should be ruled under the condition of continu- ous operation.

Prospects of effective microorganisms technology in wastes treatment in Egypt

Sludge dewatering and treatment may cost as much as the wastewater treatment.Usually large proportion of the pollutants in wastewater is organic.They are attacked by saprophytic microorganisms,i.e.organisms that feed upon dead organic matter.Activity of organisms causes decomposition of organic matter and destroys them,where the bacteria convert the organic matter or other constituents in the wastewater to new cells,water,gases and other products.Demolition activities,including renovation/remodeling works and complete or selective removal/demolishing of existing structures either by man-made processes or by natural disasters,create an extensive amount of wastes.These demolition wastes are characterized as heterogeneous mixtures of building materials that are usually contaminated with chemicals and dirt.In developing countries, it is estimated that demolition wastes comprise 20%to 30%of the total annual solid wastes.In Egypt,the daily quantity of construction and demolition(C&D) waste has been estimated as 10 000 tones.That is equivalent to one third of the total daily municipal solid wastes generated per day in Egypt.The zabbaliin have since expanded their activities and now take the waste they collect back to their garbage villages where it is sorted into recyclable components:paper,plastics, rags,glass,metal and food.The food waste is fed to pigs and the other items are sold to recycling centers.This paper summarizes the wastewater and solid wastes management in Egypt now and future.

Mixed convection in gravity-driven nano-liquid film containing both nanoparticles and gyrotactic microorganisms

Analysis of a gravity-induced film flow of a fluid containing both nanoparticles and gyrotactic microorganisms along a convectively heated vertical surface is presented.The Buongiorno model is applied. Two kinds of boundary conditions, the passive and the active boundary conditions, are considered to investigate this film flow phenomenon.Through a set of similarity variables, the ordinary differential equations that describe the conservation of the momentum, the thermal energy, the nanoparticles, and the microorganisms are derived and then solved numerically by an efficient finite difference technique.The effects of various physical parameters on the profiles of momentum, thermal energy,nanoparticles, microorganisms, local skin friction, local Nusselt number, local wall mass flux, and local wall motile microorganisms flux are investigated. It is expected that the passively controlled nanofluid model can be much more easily achieved and applied in real circumstances than the actively controlled model.

Treatment of Phenol-Contaminated Soil by Potassium Ferrate Based on pH Control

This study aims to optimize the treatment of phenol-contaminated soil by potassium ferrate. Variations in pH value can accurately reflect the state and reaction status of the entire treatment process. Therefore, the pH value could be an important variable for optimizing the reaction conditions and achieving the automatic control of the process. About 99.89% of phenol was removed after 10 min of the pH-contxolled reaction at a rotational speed of 40-70 r/min, with the initial phenol concentration equating to 10.0 g/kg and the total water consumption reaching 2.72 L （at a soil/water ratio of 1：0.68）. The test results could provide a basis for practical application of automatic reaction control by pH value.

Bacterial contamination of orally-consumed crude herbal remedies:A potential source for multi-drug resistant pathogens in man

Objective:The acceptability of herbal remedies for alleviating discomforts and ill-health has become very popular, on the account of the increasing cost of allopathic medicine for personal health maintenance.The observable non-adherence of herbalists to the established World Health Organization(WHO) / National Agency for Food and Drug Administration Control(NAFDAC) regulations for the quality control of herbal medicines is an issue for concern.In view of this,34 popular and widely consumed crude herbal remedies in southwestern,Nigeria were screened for compliance with standard limits for bacterial contamination,bacteria flora and their antibiotic susceptibility pattern.Methods:Isolates recovered from samples were identified using the cultural, morphological and biochemical characteristics.They were also tested for drug sensitivity using standard procedures. Results:A heavy bacteria load ranging from 3.00×10~3-9.58×10~5 CFU/ML and 1.20×10~5- 5.41×10~5 CFU/ML was observed for water and spirit extracted preparations respectively.The bacteria flora cum contaminants were:Staphylococcus aureus,Bacillus cereus,Bacillus subtilis,Pseudomonas aeruginosa, Micrococcus luteus,Lactobacillus plantarum,Klebsiella pneumoniae,Escherichia coli,streptococcus,Shigella, Neisseria,Arthrobacter,Kurthia and Clostridium species.All the isolates were multi-drug resistant(MDR) strains.Conclusion:The crude herbal preparations consumed in Nigeria failed to comply with the internationally recognized standards regarding bacteria load and flora.The presence of MDR pathogens is of greatest concern. It poses a great risk to consumers health and could be a source of introducing MDR organisms into the human population.There is the need for the enforcement of established guidelines to ensure the safety of these preparations.

Numerical Study on Effects of Door-Opening on Airflow Patterns and Dynamic Cross-Contamination in an ISO Class 5 Operating Room

The contamination diffusion to the operating room when the door is open was simulated with a computational fluid dynamic(CFD) method,to give the extent of the contamination diffusion.The influence of the door-opening procedure was ignored since the door of the operating room is normally a sliding one.The flow field in the case of the 16 s course of opening the door was simulated.The simulated and the experimental results demonstrate that the extent of the contamination diffusion is around 1.5 m when there is no temperature difference between indoor and outdoor,and there is hardly any contamination diffusion when the temperature difference is 1 ℃.It can be concluded that the positive pressure difference in the operating room lost its function in preventing the contamination when the door is open.That the temperature of corridor is lower than that of operating room contributes to contamination control.Keeping 1 ℃ temperature difference between corridor and operating room and increasing positive pressure and air flow are suggested.It is more secure to set up an anteroom if persons come in or out of the operation room at the course of surgery.

Renewed Focus on the Threat of Cross-Contamination in Molecular Laboratories: Notes from the COVID-19 Testing Experience in Bangladesh

Rapid and accurate laboratory diagnosis of SARS-CoV-2 infection is crucial for the management of COVID-19 patients and control of the spread of the virus. At the start of the COVID-19 pandemic, Bangladesh had only one government molecular laboratory where real-time RT-PCR would be performed to diagnose SARS-CoV-2 infection. With the increasing number of suspected cases requiring confirmation diagnostic testing, there is a requirement to expand capacity for large-scale testing quickly. The government of Bangladesh established over 100 molecular laboratories within one year to test COVID-19. To expand the testing capacity, the government was compelled to recruit laboratory staff with limited experience and technical expertise, especially in molecular assays, to process specimens, interpret results, troubleshoot. As a result, the risk of diagnostic errors, such as cross-contamination, increased, potentially undermining the efficacy of public health policies, public health response, surveillance programs, and restrictive measures aimed toward containing the outbreak. In this piece, we discuss the different sources of cross-contamination in the COVID-19 RT-PCR laboratories and proffer practical preventive measures to avoid them.

Integrated Biological Control of Tobacco Bacterial Wilt (<i>Ralstonia solanacearum</i>) and Its Effect on Rhizosphere Microbial Community

Biological control agents and soil amendments have been applied to control tobacco bacterial wilt, but the mechanism is not well-known. In the present study, a field experiment was performed to investigate the soil physicochemical properties, disease index (DI) and disease incidence of tobacco bacterial wilt, and rhizosphere microbial community. The results show that the control efficacy of single application of antagonistic bacteria and calcium cyanamide was 46.43% and 51.92%, respectively. While the combined control efficacy of antagonistic bacteria and calcium cyanamide was 65.79%. Besides, the combined application of antagonistic bacteria and calcium cyanamide could increase soil pH, total N alkaline N, and exchangeable Ca, which were negatively associated with the microbial diversity, soil-borne pathogenic microorganisms, and incidence of tobacco bacterial wilt. Additionally, the combination of antagonistic bacteria and calcium cyanamide can improve the proportion of some antagonistic microbial species, and these antagonistic microbial species were inversely associated with the DI of tobacco bacterial wilt. In conclusion: The integrated measure may influence soil microbial communities through enhancing soil physicochemical properties and rebuild healthy soil microbial community structure to mitigate tobacco bacterial wilt. The current study presented valuable insights into the mechanisms enhancing soil health in the integrated measure.

Chromium accumulation, microorganism population and enzyme activities in soils around chromium-containing slag heap of steel alloy factory

The environmental risk of chromium pollution is pronounced in soils adjacent to chromate industry. It is important to investigate the functioning of soil microorganisms in ecosystems exposed to long-term contamination by chromium. 45 soil samples obtained from different places of the slag heap in a steel alloy factory were analyzed for chromium contamination level and its effect on soil microorganisms and enzyme activities. The results show that the average concentrations of total Cr in the soil under the slag heap, adjacent to the slag heap and outside the factory exceed the threshold of Secondary Environmental Quality Standard for Soil in China by 354%, 540% and 184%, respectively, and are 15, 21 and 9 times higher than the local background value, respectively. Elevated chromium loadings result in changes in the activity of the soil microbe, as indicated by the negative correlations between soil microbial population and chromium contents. Dehydrogenase activity is greatly depressed by chromium in the soil. The results imply that dehydrogenase activity can be used as an indicator for the chromium pollution level in the area of the steel alloy factory.

Microbial Community from MTBE-Contaminated Soil for Aerobic Biodegradation of MTBE

This Methyl tert-butyl ether (MTBE) is one of the main additives in gasoline to increase octane rating and consequently reduce air pollution. The physico-chemical properties of this substance (high water solubility, low sorption in soil) result in high mobility and considerable concentrations in aquifers. In this survey, Isfehan Refinery that was encountered with MTBE contamination problem was selected as a case study and the MTBE degradation ability of this contaminated area by its indigenous microorganisms was investigated. In the first step of this survey, the influence of various factors on the aerobic degradation of MTBE such as mixed culture type, incubation time, microbial culture and optimal concentration of MTBE were investigated in shaking flasks and the most important factors were specified by means of fractional factorial design 1/2. In the second stage by using optimal values which obtained from the first stage, the effects of co-substare parameter and inoculum parameter were assayed by means of response surface method. The results of the experiments showed that the mixed culture type and initial concentration of MTBE were the most significant factors. The results of the experiments showed that the mixed indigenous culture acted better than activated sludge. The initial concentration of MTBE was also one of the most significant factors. At the best condition about 31 percent of MTBE was treated by co-substrating with n-hexane in a ratio of 0.2.

Indoor biology pollution control based on system-based humidity priority control strategy

Indoor biological contamination and HVAC system secondary contamination problems caused wide public concerns. Biological contamination control will be the next step to achieve better IAQ. The most efficient and safe way to control biological contamination was to limit relative humidity in HVAC system and conditioned environment in the range that is more unsuitable for microorganism to survive. In this paper,by referring to bio-clean project experiences,a system-based humidity priority control manner came into being by lowering outdoor air humidity ratio to eliminate all indoor latent load and using self recirculation units to bear indoor sensible load. Based on the whole-course residue humidity contaminant control concept,dynamic step models for coil and conditioned zone were developed to describe mass and energy conservation and transformation processes. Then,HVAC system and conditioned zone dynamic models were established on LabVIEW+Matlab platform to investigate optimized regulation types,input signatures and control logics. Decoupling between cooling and dehumidification processes can be achieved and a more simplified and stable control system can be acquired by the system-based humidity priority control strategy. Therefore,it was a promising way for controlling biological pollution in buildings in order to achieve better IAQ.

Detention basins as best management practices for water quality control in an arid region

Flood control detention basins （DBs） can act as water quality control structures or best management practices （BMPs）. A key pollutant that DBs serve to settle out is particulate phosphorus, which adsorbs onto sediment. This study examines the sediment phosphorus concentration and its relationship with the particle size of sediment microcosms from pre- and post-rain event samples obtained from six DBs located in Clark County, Nevada. DBs were allotted a land use classification to determine if there was a correlation between the sediment phosphorus concentration and surrounding land use. The curve number method was used to calculate the runoff and subsequent phosphorus carried into the DB by the runoff. Our data show sediment phosphorus concentrations to he highest in soils from undeveloped areas. Runoff amount also plays a substantial role in determining the amount of phosphorus brought into the DB by sediment. This research has implications for improvement of water quality in arid regions.

Pollution and Control Measures in Plant Tissue Culture in Orchid Plant

Contamination is a phenomenon that often occurs in the operation of plant tissue culture,and it is also one of the three major problems in plant tissue culture.Compared with browning and vitrification,contamination is more likely to occur,which brings great harm to scientific research and production practice.Its appearance will greatly affect the normal growth and differentiation of tissue culture materials,and will reduce the yield of cultivated plants to a certain extent.Therefore,we cannot underestimate any step in the tissue culture operation.This study summarized the reasons for its occurrence and how to formulate prevention and control measures based on recent research combined with the actual situation.

Radiological and X-Ray Diffraction Characterization of Bauxite and Rutile Ore Contaminated Environment in Kanam and Wase Mineral Exploration Sites, Plateau State-Nigeria

Two non-destructive analytical techniques (gamma spectrometer and X-ray diffractometer) were employed in the analysis of bauxite and rutile ore and their vicinity soil and control sourced within the Kanam and Wase mineral exploration sites. The activity concentrations of natural radionuclides 238U, 232Th, and 40K in the soil samples received from bauxite and rutile mineral mining vicinities revealed high concentrations of 238U, 232Th, and 40K compared to the control soil samples sourced 500 m away from the mineral exploration vicinities. Radiological detriments RLI, AUI, Hin and Hex unveiled values exceeding the radiation standard concentration (>1) for soil. X-ray diffraction characterization of bauxite ore revealed the interlocking minerals of Bauxite (18)%, Albite (11)%, Garnet (15)%, Illite (6)% and Muscovite (43)% in various proportions obtained within the 2θ range (9.18 to 64.4) and a peak value (intensity, cps) of 3400. Pure bauxite percentage in the ore meets metallurgical grade (15 - 25)%. X-ray diffraction of rutile ore revealed the minerals of rutile (40)%, quartz (21.4)%, ilmenite (27)% and garnet (11.8)% found within the 2θ range (27.5 to 35.6) and a peak value intensity of 31.1 - 100.0 cps also meeting the metallurgical grade of 15% - 25%. The major environmental concern associated with the mineral-sands industry is the radiation hazards, pollution of ground-water sources from heavy metals, mineral transport with heavy equipment’s, dredging operations in fragile coastal area and clearing of vegetation.

Water Quality Microbiological Inspection and Quality Control Technology

People’s lives are strongly linked to the quality of their drinking water.The quality of drinking water can be successfully ensured by testing microorganisms in water quality samples and examining their unqualified variables.Many urban residents’drinking water contains a variety of microorganisms,which will have a direct impact on the quality of the water,and all microorganisms will offer a health risk.As a result,steps should be taken to eliminate germs.As a result,the focus of this article is on water quality microbiological inspection and quality control technology.

基于位置分配的去蜂窝massive MIMO系统导频分配功率控制算法

针对去蜂窝(cell free,CF)大规模多输入多输出(multiple-input multiple-output,MIMO)系统中存在严重的导频污染问题,提出了一种基于位置分配的贪婪导频分配功率控制算法(greedy pilot assignment based on location with pilot power control,GPABL with PPC).首先,遵循相邻用户不分配相同导频序列的原则进行贪婪导频分配(greedy pilot assignment,GPA);然后,在导频分配的基础上叠加了导频功率控制,选择合理的导频功率控制系数减小信道估计的均方误差.仿真结果表明,将两种方式结合起来进行导频优化,系统的吞吐能力有所提升.