Microbiological Quality of “Rabilé”, a Yeast Used for Fermentation of Dolo, a Local Beer in Dédougou, Burkina Faso

Sorghum beer or dolo is part of the eating habits of part of the population of Dédougou because of its low price compared with industrial beers. Its production is an ancestral tradition that uses traditional equipment and gives dolo organoleptic properties that are not found in industrial beers. The production process involves several stages, including fermentation, which itself comprises natural lactic fermentation followed by alcoholic fermentation using traditional yeasts, which are not controlled in any way. The general aim of this study is to assess the microbiological quality of these fermentative yeasts in the town of Dédougou, in order to contribute to the health safety of the population and the promotion of these local beers. Twenty samples of fermenting yeast were analyzed according to ISO standards, to isolate enterobacteria, total and faecal coliforms according to standard procedures for isolating these micro-organisms. The isolated strains were identified using the API20E gallery. Microbiological analyses revealed the presence of 51.17% enterobacteria, 45.38% total coliforms and 3.45% thermotolerant coliforms. We counted 40% Escherichia coli, 20% Enterobacter cloacae, 20% Klebsiella pneumoniae and 20% Klebsiella spp. All the strains detected are capable of surviving in hostile conditions and could harm the quality of the dolo, consumer health and cause real collective food poisoning in the town of Dédougou. This enabled us to assess the microbial quality of these yeasts and to propose more suitable measures for producing and preserving dolo under hygienic conditions to protect consumer health.

Microbiological Quality of Cyperus esculentus L. Products Sold in Ouagadougou and Bobo Dioulasso (Burkina Faso)

This study aimed to assess the microbiological quality of tiger nut (Cyperus esculentus L.) products sold in Ouagadougou and Bobo Dioulasso. The microbial load of tubers and tiger nut milk was determined using ISO 4833-1 (2003) standard (total mesophilic aerobic flora), NF ISO 7954 (1998) standard (yeasts and molds), and ISO 4832 (2006) standard (total coliforms, thermotolerant coliforms). The results showed that tiger nut tubers had an average microbial load between 4.86 ± 7.03 × 106 UFC/g and 1.82 ± 2.30 × 107 UFC/g for total mesophilic aerobic flora, from 4.34 ± 10.6 × 105 UFC/g to 3.52 ± 4.54 × 106 UFC/g for yeasts and molds, from 2.23 ± 2.25 × 105 UFC/g to 1.41 ± 2.16 × 105 UFC/g for total coliforms and from 1.83 ± 2.03 × 105 UFC/g to 7.0 ± 10.8 × 104 CFU/g for thermotolerant coliforms. For tiger nut milk samples, the average microbial load varied from 3.48 ± 2.98 × 106 CFU/g to 2.80 ± 5.69 × 107 CFU/g for total mesophilic aerobic flora, from 5.00 ± 7.21 × 104 CFU/g to 1.88 ± 3.31 × 105 CFU/g for yeasts and molds, from 4.58 ± 10.4 × 104 CFU/g to 6.31 ± 9.17 × 105 CFU/g for total coliforms and 7.00 ± 7.00 × 103 CFU/g to 2.87 ± 5.86 × 105 CFU/g for thermotolerant coliforms. This study revealed that the tubers and tiger nut milk sold in Ouagadougou and Bobo Dioulasso had a high microbial load which could lead to the degradation of these products and food poisoning for consumers.

Food Microbiology and Safety 实验课的教改探索

该文作者所在大学与新西兰梅西大学合作开展了食品科学与工程专业国际化培养本科教育项目,全英文课程Food Microbiology and Safety是该项目的核心课程之一。该实验课以应用性为前提,以课程思政为引领,强调食品微生物学与食品安全学的融合,中外师资合作开展了系列教学探索与实践。课程设计以食品产品和食品生产为情境,以微生物安全为话题,模拟真实生产场景,丰富内涵和拓展外延;自主设计实验激发主观能动性、自主规划进程锻炼统筹能力、线上资源平台支撑自主学习与评价、随机分组培养团队合作能力。实践表明,课程有效实现了食品微生物学与食品安全学的有机融合,目标驱动型实验教学过程更利于激发学生的主动性,大量综合性和设计性实验提高了课程的两性一度。与同期对照班级相比,该项目所培养学生具有更强的专业素养和实践能力,为食品专业其他实验课程的教学改革提供了参考。

Electrochemical behavior of microbiologically influenced corrosion on Fe_3Al in marine environment

In this article, microbiologically influenced corrosion behavior of Fe3Al intermetallie compound in microorganism culture medium has been investigated by using weight loss methods, electrochemical techniques, and electron microscopy. Polarization curves showed that a sharp electrical current peak caused by surface pitting could be observed after Fe3Al electrodes were immersed in culture medium for 15 days when the polarization potential was about -790 mV vs SCE. Based on the electrochemical impedance spectroscopy （EIS） and the equivalent circuit parameters of the associated system, the corrosion products were found to exhibit a two-layer structured feature and the microorganisms could induce pitting and erosion corrosion of the inner layer. In addition, the passivating film of the inner layer was absolutely destroyed by microbial metabolic products.

Study of Microbiologically Induced Corrosion Action on Al-6Mg-Zr and Al-6Mg-Zr-Sc

The corrosion behaviors of Al-6Mg-Zr and Al-6Mg-Zr-Sc in the sulfate-reducing bacteria （SRB） solution in anaerobic environment were studied using electrochemical, microbiological, and surface analysis methods. It was found that the oxide film was more compact owing to the addition of Sc resulting in the open circuit potential shifting by about 100mV positively. On the other hand, it was seen that the pitting sensitivity of Al-6Mg-Zr-Sc alloy in SRB solution decreased and its microbiologically influenced corrosion resistance was improved. Pitting corrosion occurring on the surface of the two alloys under the comprehensive action of the metabolism of SRB was observed by SEM. It was obtained by EDS that the corrosion degree increased with time and corrosion was furthered by deposition of the product.

A novel and rapid microbiological assay for ciprofoxacin hydrochloride

The present work reports a simple, fast and sensitive microbiological assay applying the turbidimetric method for the determination of ciprofloxacin hydrochloride （CIPRO HC1） in ophthalmic solutions. The validation method yielded good results and included excellent linearity, precision, accuracy and specificity. The bioassay is based on the inhibitory effect of CIPRO HC1 upon the strain of Staphylococcus epMermidis ATCC 12228 used as the test microorganism. The results were ar, ated statistically by analysis of variance （ANOVA） and were found to be linear （r=0.9994, in the range of 14.0-56.0 lag/mL）, precise （intraday RSD %=2.06; interday RSD%=2.30） and accurate （recovery = 99.7%）. The turbidimeaic assay was compared to the UV spectrophotometric and I-IPIX2 methods for the same drug. The tuIbidimetric bioassay described on this paper for determination of ciprofioxacin hydrochloride in ophthalmic solution is an alternative to the physicochemical methods disclosed in the literature and can be used in quality control routine.

THE ELECTROCHEMICAL BEHAVIOR OF OCEANIC MICROBIOLOGICAL INFLUENCED CORROSION ON CARBON STEEL

The corrosion behavior of carbon steel in the medium of marine microorganisms was investigated by electrochemical impedance spectra, polarization curves, and so on. Experimental results showed that the corrosion potential of carbon steel moved in a negative direction in the unpurified marine microorganism solution, and the polarization style of the cathodic process did not change. The electrochemical impedance spectra showed that the impedance value of the electrode decreased in the medium with bacteria, which indicated that the existence of microorganism could accelerate the corrosion progress of carbon steel.

Microbiological Quality of Chicken Sold in Accra and Determination of D₁₀-Value of <i>E. coli</i>

Chicken is an excellent source of good quality protein, but it is highly susceptible to microbial contamination and often implicated in food borne disease. The microbiological quality of chicken at different retail outlets (supermarkets, local markets and farms) in Accra was investigated, and D10-values of E. coli in refrigerated and frozen retailed chicken was determined. The microbiological quality of chicken was studied by analyzing 27 chicken thigh samples collected from the retail outlets. D10-value of Escherichia coli was determined by using a linear regression model after gamma irradiation of inoculated chicken samples with doses of 0, 150, 300, 450, 600, 750 and 900 Gy. Mean total viable counts for the supermarkets, local markets and farms were 6.46, 6.91 and 6.57 log10 cfu/g respectively. Mean total coliform counts for the supermarkets, local markets and farms were 3.80, 3.46 and 3.14 log10 cfu/g respectively and the mean S. aureus counts were also 2.32, 2.28 and 2.70 log10 cfu/g respectively. There were no significant differences (p > 0.05) between the mean total viable count, total coliform counts and S. aureus count for the supermarkets, local markets and the farms. Mean counts of E. coli detected at the supermarket, local markets and farms were 1.27, 2.59 and 2.74 log10 cfu/g respectively. Salmonella spp. was detected in 2 out of the 27 samples. Fifty-two percent and 70% of samples respec-tively had total viable counts and total coliform counts within the microbial safety standards. Mean D10E. coli were 0.22 and 0.32 kGy in refrigerated and frozen chicken respectively. Presence of pathogenic bacteria in fresh chicken sold in some retail outlets in Accra was confirmed. Low D10-values of E. coli especially under refrigerated conditions suggest susceptibility to low dose irradiation and possibility of controlling spoilage and pathogenic microflora of fresh poultry.

Microbiological assessment of indoor air of a teaching hospital in Nigeria

Objective:To investigate the quality of indoor air of different wards and units of Olabisi Onabanjo University Teaching Hospital, Sagamu, to ascertain their contribution to infection rate in the hospital.Methods:The microbial quality of indoor air of nine wards/units of Olabisi Onabanjo University Teaching Hospital, Sagamu, Nigeria was conducted. Sedimentation technique using open Petri-dishes containing different culture media was employed and samplings were done twice daily, one in the morning shortly after cleaning and before influx of people/patients into the wards/units and the other in the evening when a lot of activities would have taken place in these wards. Isolates were identified according to standard methods.Results:Results showed that there was a statistically significant difference(氈2= 6.0167) in the bacteria population of the different sampling time whereas it was not so for fungi population(氈2= 0.2857). Male medical ward(MMW) and male surgical general(MSG) recorded the highest bacterial and fungal growth while the operating theatre(OT) was almost free of microbial burden. The bacteria isolates were Staphylococcus aureus, Klebsiellasp., Bacillus cereus, Bacillus subtilis, Streptococcus pyogenes andSerratia marscenceswhile the fungi isolates includedAspergillus flavus, Penicilliumsp.,Fusariumsp.,Candida albicansandAlternariasp.Staphylococcus aureuswas the predominantly isolated bacterium whilePenicilliumsp. was the most isolated fungus.Conclusions:Though most of the microbial isolates were potential and or opportunistic pathogens, there was no correlation between the isolates in this study and the surveillance report of nosocomial infection during the period of study, hence the contribution of the indoor air cannot be established. From the reduction noticed in the morning samples, stringent measures such as proper disinfection and regular cleaning, restriction of patient relatives' movement in and out of the wards/units need to be enforced so as to improve the quality of indoor air of our hospital wards/units.

Microbiological indication of municipal solid waste landfill non-stabilization

Accidental collapse resulted from unstable factors is an important technological problem to be solved in sanitary landfill. Microbiological degradation of organic matters in landfilled solid waste are an important unstable factor. A landfill reactor was thus manufactured and installed to examine quantitative and population dynamics of microorganisms during degradation of landfilled solid waste. It was showed that unstable landfill can be reflected and indicated by microbiological features such as rapidly decreased growth amount of microorganisms, no detection of fungi and actinomyces, and changing the dominant population into methanogenic bacteria and Acinotobacter.

SpyGlass application for duodenoscope working channel inspection: Impact on the microbiological surveillance

BACKGROUND Patient-ready duodenoscopes were designed with an assumed contamination rate of less than 0.4%;however,it has been reported that 5.4%of clinically used duodenoscopes remain contaminated with viable high-concern organisms despite following the manufacturer’s instructions.Visual inspection of working channels has been proposed as a quality control measure for endoscope reprocessing.There are few studies related to this issue.AIM To investigate the types,severity rate,and locations of abnormal visual inspection findings inside patient-ready duodenoscopes and their microbiological significance.METHODS Visual inspections of channels were performed in 19 patient-ready duodenoscopes using the SpyGlass visualization system in two endoscopy units of tertiary care teaching hospitals(Tri-Service General Hospital and National Taiwan University Hospital)in Taiwan.Inspections were recorded and reviewed to evaluate the presence of channel scratches,buckling,stains,debris,and fluids.These findings were used to analyze the relevance of microbiological surveillance.RESULTS Seventy-two abnormal visual inspection findings in the 19 duodenoscopes were found,including scratches(n=10,52.6%),buckling(n=15,78.9%),stains(n=14,73.7%),debris(n=14,73.7%),and fluids(n=6,31.6%).Duodenoscopes>12 mo old had a significantly higher number of abnormal visual inspection findings than those≤12 mo old(46 findings vs 26 findings,P<0.001).Multivariable regression analyses demonstrated that the bending section had a significantly higher risk of being scratched,buckled,and stained,and accumulating debris than the insertion tube.Debris and fluids showed a significant positive correlation with microbiological contamination(P<0.05).There was no significant positive Spearman’s correlation coefficient between negative bacterial cultures and debris,between that and fluids,and the concomitance of debris and fluids.This result demonstrated that the presence of fluid and debris was associated with positive cultures,but not negative cultures.Further multivariate analysis demonstrated that fluids,but not debris,is an independent factor for bacterial culture positivity.CONCLUSION In patient-ready duodenoscopes,scratches,buckling,stains,debris,and fluids inside the working channel are common,which increase the microbiological contamination susceptibility.The SpyGlass visualization system may be recommended to identify suboptimal reprocessing.

Research Progress in Microbiological Degradation of Bensulfuron-Methyl Herbicide

This paper reviewed the strategies and methods of screening for microorganisms having strong ability bensulfuron-methyl （BSM）, and discussed BSM degradation pathways and factors affecting its microbial metabolism prospected the research emphasis in the future to remove Finally, it

Microbiological Quality of Asadero Cheese Manufactured with a Plant Based Coagulant from <i>Solanum elaeagnifolium</i>

In Chihuahua, north Mexico, the berries of Solanum elaeagnifolium (trompillo or silverleaf nightshade) have been used in the manufacture of artisanal filata-type asadero cheese. Solanum elaeagnifolium is a wild plant that possesses proteases in its fruit;those enzymes exhibit general proteolytic activities, which are useful in traditional asadero cheesemaking as a rennet substitute. These type of cheese is softer than those made with rennin or chymosin due to their water content and proteolysis. Thus, the aim of this work was to explore microbiological susceptibility of asadero cheese made with an extract from ripe berries and compared with those elaborated with commercial rennet. Crude extract of such fruit was obtained by salting out with ammonium sulfate (40%). Cheeses were obtained by a standardized process only changing the enzyme, packaged in plastic bag or vacuum bag and storage at 4℃ -?6℃. The study included the analysis of spoilage bacteria (total aerobic count, yeasts and molds), indicators of hygiene (total coliforms and E. coli) and fecal contamination (fecal coliforms) after 1, 7, 14, 21 and 28 days of production. Although cheese made with S. elaeagnifolium had lower microbial growth, the aerobic count and yeasts and molds count of all cheese samples showing a 28 days shelf life. Total coliforms, in limits beyond the established ones by the Mexican legislation for human consumption with no effect of the enzyme type used for production, as well as for fecal coliforms. Differences were detected just for packaged method, suggesting that good manufacturing practices take place not the plant coagulant.

Microbiological Evaluation of Prepared/Cooked Foods in a HACCP Environment

In the production of safe food, a multitude of factors and elements along the food chain are involved. For this study we have established three factors relative to the food that have the possibility of influence on its microbiology content: basic ingredients, conservation time in refrigeration and handling degree. In the samples we looked forward three types of germens: warning, witness and pathogen. We did not find significant differences in the groups considered with regard to the variable of reference.

Microbiologically influenced corrosion of cable bolts in underground coal mines:The effect of Acidithiobacillus ferrooxidans

Reports on corrosion failure of cable bolts,used in mining and civil industries,have been increasing in the past two decades.The previous studies found that pitting corrosion on the surface of a cable bolt can initiate premature failure of the bolt.In this study,the role of Acidithiobacillus ferrooxidans(A.ferrooxidans)bacterium in the occurrence of pitting corrosion in cable bolts was studied.Stressed coupons,made from the wires of cable bolts,were immersed in testing bottles containing groundwater collected from an underground coal mine and a mixture of A.ferrooxidans and geomaterials.It was observed that A.ferrooxidans caused pitting corrosion on the surface of cable bolts in the near-neutral environment.The presence of geomaterials slightly affected the p H of the environment;however,it did not have any significant influence on the corrosion activity of A.ferrooxidans.This study suggests that the common bacterium A.ferrooxidans found in many underground environments can be a threat to cable bolts'integrity by creating initiation points for other catastrophic failures such as stress corrosion cracking.

Microbiological Pollution Indication as Tracer for the Pollution of Well Water: The Example of the District of Abomey-Calavi (Benin)

Water is indispensable at life. Resources in waters of the township of Abomey-Calavi are of national importance. The township of Abomey-Calavi is very close to the biggest plan of water Beninese lagoon: The Nokoué lake. Besides, not only the waters of the ground water are consumed by the majority of the population from the traditional well, but also, the underground waters of the terminal continnental of the township of Abomey-Calavi are exploited intensely by the Society Nationnale of the Waters of Benin (SONEB) to nourish in drinking water in the townships of Abomey-Calavi, of Cotonou the biggest city of the country and Sèmè. The microbiological parameter followup (total coliforms, coliforms thermotolerants and enterrococcis) to the level of many traditional well and deep boring and some different points of Nokoué lake were the object of a treatment of data by the establishment of card of fecal contamination of waters natural of the region, that informs us on the quality of waters by the slant of a microbiological quality indication that calculates itself according to the method of Bovesse and Depelchin (1980). The survey of the microbiological contamination indication, succeeds to the establishment of seasonal cards of quality of waters.

Integration of Commercial Microbiological Products into Soil Fertility Practices as a Potential Option for Acclimatization and Growth of TC Banana in Kenya

Tissue culture (TC) banana plantlets at the in vitro stage are delicate and devoid of microbes and nutrients that are essential for establishment and subsequent growth. Some microbes are known for function best under certain soil threshold levels of macro and micronutrients and have been associated with growth and performance of TC banana. A green house and field study was conducted to evaluate the effect of combining two commercial biological products [Rhizatech and ECO-T (mycorrhiza and Trichoderma based products, respectively)] with various sources of nitrogen and phosphorous including Mavuno, Minjingu phosphate rock, Calcium Ammonium Nitrate (CAN), manure and diammonium phosphate (DAP) on growth and performance of TC banana in Vertisol and Rhodic Ferralsol soil conditions. Tissue culture plants were initially inoculated with Rhizatech and ECO-T at the acclimatization stage and subsequently at the beginning of the potting stage and field establishment. Addition of nutrient sources was also done at the same stages of plant growth by mixing with the soil substrates prior to planting. The performance of plants was significantly (at p ≤ 0.05) affected by the combinations of nutrient sources depending on the soil type and stage of plant development. The growth of plants in the Vertisol increased with Trichoderma combined with either organic manure, DAP or combined with a macro and micro nutrient source (Mavuno) as compared to the sole application of Trichoderma. Performance of plants treated with combination of mycorrhiza and either Mavuno and minjigu rock phosphate was consistently higher in the Rhodic Ferralsol than either mycorrhiza alone or fertilizer alone. This indicates that TC plants could highly benefit from combined application of microbiological products and inorganic and organic fertilizers. However, a prior knowledge of the product’s microbial formulation and prevailing soil conditions is essential for optimizing the potential benefits of integrating microbe-based product with inorganic and organic fertilizers.

Microbiological Quality Assessment of Drinking Water in Lalo Commune, Benin (West Africa)

Although drinking water is readily available in Benin, its quality presents a public health concern. The district of Ahomadégbé in the commune of Lalo is characterized by several artesian wells. Unfortunately, anthropogenic factors negatively affect the drinking water quality in this area. The aim of this research was to study the microbiological quality of drinking water in the Ahomadégbé district, and to review household water treatment methods employed by the local population. Thirty-five water samples were taken—at water collection points, at selected points along the water transportation system and from water storage facilities, and microbiological parameters were measured. Qualitative data were collected via in-depth interviews with key informants regarding local household water treatment methods. Results reveal that there is a significant degree of microbiological pollution of drinking water in this district, particularly during the water transportation and storage stages where microbiological pollution exceeds levels approved by the World Health Organization. Local residents are familiar with several household water treatment methods. However, these methods are inconsistently applied, which limits their effectiveness. In addition to improving the quality of the drinking water resource itself, it is important to set up interventions relating to water treatment methods in local households.

Tree encroachment into savannas alters soil microbiological and chemical properties facilitating forest expansion

Abstract Forests have been expanding over typical savanna sites for the past 3000 years in the Neotropics. Such invasion can produce a series of environmental modifications on typical savanna; however, it remains unclear how modifications in soil properties, caused by the encroachment of woody species, facilitate the expansion of forest ecosystems under dystrophic conditions. Here we examined chemical and microbiological changes associ- ated with tree encroachment in oxisols of a Neotropical Savanna at Assis Ecological Station, Southeastern Brazil. We predicted that tree encroachment caused by typical forest species would cause significant changes in the chemical and microbiological properties of savanna soils. Soils were sampled at Assis Ecological Station, from savanna sites differing in tree encroachment （typical, dense and forested savanna） caused by decades of fire exclusion. We analysed vegetation leaf area index and leaf litter volume deposited in the studied plots and chemical （pH,organic matter, P, K, Ca, Mg, A1, NO3-, NH4＋） and microbiological （microbial C biomass and dehydrogenase activity） properties of soils under distinct encroachment conditions. Most soil chemical properties did not change along the tree encroachment gradient; however, total P, soil organic matter, soil microbial C and dehydrogenase activity increased from typical savanna to forested savanna. The changes in soil organic matter and dehydrogenase activity were correlated with the values of leaf area index and litter volume along the encroachment gradient. Our results demonstrate that forest species can increase carbon and phosphorus supplies in tropical savanna soils.