Microbiological Quality Indices Research Articles

The impact of heavy metal contamination on soil quality and plant nutrition. Sustainable management of moderate contaminated agricultural and urban soils, using low cost materials and promoting circular economy

A three-year experiment was conducted over six different soils, from northern and central Greece. The soils samples derived from both rural and urban environments, and they were moderately contaminated with heavy metals (Cu, Cd, Pb, Zn). Experiments were carried out by adding crop residues of wheat straw, cultivated in the plain of Thessaly, in the soil samples. Preliminary experiments were carried out to find the optimal mixing ratio of straw with soils, as well as the cut size, the temperature and humidity of the straw before its incorporation. The addition of wheat straw caused significant changes in the visual, physical, chemical, nutritional and microbiological quality indices of the soils studied. The indices related to the fertility and nutritional capacity of the soil samples were, in most cases, significantly improved, enhancing the soil health. Furthermore, the use of the straw reduced the availability of toxic metals, increasing, on the other hand, the availability of trace elements. Although the use of straw for improving soil properties has been known since ancient times, its use for polluted soil remediation is a matter of concern. A significant number of environmental and economic problems could be addressed if the principles of the circular economy were taken into account by decision-makers. Wheat straw, could be a key factor for soil health improvement, increasing its fertility and limiting the risks of toxic pollutants.

Assessment of Health Risks Posed by Water Quality in the Centralized Supply Network of Private Sector Housing in Ufa

Background: At present, high-quality drinking water supply is challenging due to natural and anthropogenic pollution of the environment and remains a priority. The Federal Clean Water Project is aimed at improving the communal infrastructure in order to ensure chemical and microbiological safety of supplied water and to inform the public. Objective: To assess priority health risk factors for the population of Ufa associated with tap water quality within the implementation of the Federal Clean Water Project in the Republic of Bashkortostan. Materials and methods: We used data of the regional information fund of public health monitoring on eight street water pumps located in six administrative districts of the city for 2016–2018. The organoleptic risk associated with drinking water quality was assessed according to Method Recommendations MR 2.1.4.0032–11. Population health risk assessment was carried out in compliance with conditions and requirements of Guidelines R 2.1.10.1920–04. Results: We established that chemical and microbiological quality indices of drinking water in street water pumps in 2016–2018 were below the permissible limits for all samples. Both organoleptic and non-carcinogenic risk estimates were within the acceptable range. The carcinogenic risk for the population was less than a case. Yet, the presence of trihalomethanes and herbicides in tap water sampled in Olimpiyskaya Street posed unacceptable total carcinogenic health risk. Conclusion: The study results were used to develop recommendations for appropriate preventive measures aimed to reduce chemical exposure of the population of Ufa through drinking water.

Elaboration of Whey Protein-Based Films in Food Products: Emphasis on the Addition of Natural Edible Bio-nanocomposites with Antioxidant and Antimicrobial Activity

: Food spoilage is one of the major elements of food insecurity that has acquired significant attention over recent decades due to global human population growth. Several studies have investigated increasing shelf life of food products using natural and environmentally friendly compounds. Whey protein (WP) can be an important additive material because it is well-known for its high value of nutrition and well characteristics for the formation of edible films. Furthermore, natural bioactive compounds have been incorporated with WP-based films to confer their antioxidant and antimicrobial activities. Herein, nanotechnology has been effectively potentiated the antimicrobial and antioxidant properties of WP films. A wide range of bioactive agents has been embedded in the WP films, such as essential oils (EOs), TiO2, nano-clay, and even lactic acid bacteria. The current paper reviews the antioxidant and antimicrobial effects of different types of WP films and their applications in food products. This study also discussed the impact of WP films on shelf life, chemical and microbiological quality indices of meats, processed meats, poultry meat products, and fish.

Assessment of water quality of Oum Er Rabia River by Microbiological Quality Index and Water Quality Index

Water resource management requires simple tools to enable managers to make decisions. This is the case for water quality indices that provide access to clear, synthetic and well-targeted information. In this study, we have chosen two indices based on two different approaches, the Microbiological Quality Index (MQI), which is determined from bacteriological analyses of water, and the Water Quality Index (WQI), which is based on physicochemical parameters. The Water Quality Index (WQI) shows a longitudinal upstream-downstream variation and ranges from is between five (5) (Null Faecal Contamination) at sampling point P1 and 3.4 (Moderate Fecal Contamination) at P2. The Water Quality Index (WQI) ranges from a low of 14.08 (excellent water quality) at the P1 level to a high of 93.05 at the P2 level (poor water quality) receiving wastewater discharges. The WQI results for P3 and P4, show that the water is of good quality (downstream of P2), which shows the degree of self-purification of the Oum Er Rabia River, regardless of the sampling period. Finally, the results of the MQI corroborate those obtained with the WQI for the water quality of the different sampling points.

Surface water pollution risk assessment of wadis, Mekerra and Saïda, in the North-Western of Algeria

Considered as the main stream of hydrographic network of Mactaa’s basin, in the west highlands of Algeria, both wadis, Mekerra and Saïda, are affected by pollution which is generated by anthropogenic activities. Makara and Saïda wadis cross the urban areas of Sidi-Bel-Abbes and Saïda respectively, in the west of Algeria, which constitute a real problem of human safety. In order to identify the pollution state on these wadis, samples have been collected during three periods of time (June 2011, July 2012 and April 2013) in the goal to characterize the physico-chemical and bacteriological quality of surface water.Results obtained describe clearly the existence of chemical and organic pollution in both wadis at high levels of calcium, magnesium, chlorides, nitrates, nitrites, phosphate, DBO5 and dissolved oxygen. The evaluation of organic pollution index (OPI) confirmed that there is a high organic pollution, upstream, which increases with high water passage towards urban areas of both cities (OPI).The bacteriological analysis results obtained show presence of high contents of faecal bacteria contamination (total coliforms (TC), faecal coliforms (TC) and faecal streptococci(FS))principally in wadi Saïda. The relationship between FC/FS justifies the predominance of human origin than of animal as source of contamination. While, the determination of microbiological quality index (MQI), for each wadi, confirms degradation of microbiological quality by the faecal pollution, mainly in Saïda urban area.

The effect of essential oils on quality and safety parameters of meat during its storage

This article researches the basic principles of mechanism for finding the concentrations of essential oils (EO) which are efficient for antimicrobial action, when used as a natural alternative to synthetic analogues. The effect of EO of rosemary, sage, garlic, laurel, cloves, basil and thyme on the structural components of meat, its physical and chemical, organoleptic and microbiological quality indices was studied. The effect of EO on duration of microorganisms’ growth phases is analyzed. It is shown that the reasonable concentration of the essential-oil mixture (EOM) is equal to 0.1%, since at this concentration the optimal inhibition of saprophytic microflora was provided with satisfactory organoleptic quality indices (“taste peculiar for this type of product”, “pleasant fragrance”, “spicy aroma”). The analysis of histological structural changes in muscle tissue showed that application of EOM slows down autolytic processes, which correlates with the data obtained in research of the specific electrical conductivity in water extracts from the muscle tissue. The autolysis process in the control samples was more intensive in comparison with the experimental samples stored in the EOM. Thus, by 84th hour of storage in the control sample the basophilic staining of the samples slices was observed, as well as almost complete disappearance of the striation of muscle fibers. In the muscle tissue slices the disintegration of individual fragments into myofibrils, and myofibrils into sarcomeres, was observed in form of a granular mass, sometimes enclosed in endomysium. The meat fibers were deformed and their separation was observed. The same changes with the studied samples stored in the EOM occurred only after 204 hours of storage. The above studies of changes in the specific electrical conductivity of water extract from meat during storage showed the presence of complexes of EOM components formed with proteins and lipids of muscle tissue. The obtained data are confirmed by histological studies. Thus, the use of EOM allowed elongation of the cold storage period of semi-finished natural lump products by 2.6 times, which proves the practical benefits of its use in the meat-processing industry.

Chemical characterization and assessment of surface waters’ suitability for irrigation in the mid-Seybouse wadi plain (North-Eastern Algeria)

PurposeThe present study is undertaken in the region of Guelma that is located in North-Eastern Algeria. Guelma’s agricultural plain is irrigated from the Seybouse ephemeral river (wadi). The latter collects the entire domestic and industrial wastewaters of the region that are discharged without prior treatment. Hence, the organic and biological or what so ever contributions to the wadi are capable of initiating a significant degradation of its waters’ quality and challenging their use for irrigation. The paper aims to discuss these issues.Design/methodology/approachThe interpretation of the results of three sampling campaigns for chemical and bacteriological analyzes was carried out in terms of the indices’ method (organic pollution index (OPI) and microbiological quality index (MQI)). The results were statistically assessed through the use of the principal component analysis (PCA). The OPI was calculated according to the method of Leclercq and Maquet (1987) whose principle is to classify the contents for the polluting elements into 5 classes each class corresponding to a given range for the considered parameter, and then to calculate the overall average class number for each sample. The MQI depends on the water concentrations in: the total coliforms, the fecal coliforms, and fecal streptococci. One defines five classes of concentrations for each of these parameters. The MQI is again the overall mean of the numbers for the classes for every parameter.FindingsThe OPI reflects a moderate pollution for most sampling stations. The PCA indicates that the variables controlling salinity are mainly Cl−, Na+ and SO42−. In August 2016, El-Fedjoudj pumping station shows a very strong fecal contamination. According to the recommendations of World Health Organization (1989), waters from wadi Seybouse cannot be used for the irrigation of vegetable crops if they were to be consumed raw.Originality/valueThis study has an environment impact as it reveals the need to protect surface waters used for irrigation and therefore protect consumers of raw vegetables that are to be consumed uncooked.

Inventory of Microbiological Water Quality from Some Boreholes in Zinder Region in the Republic of Niger

The present work deals with the current microbiological status of boreholes found in Zinder region in the Republic of Niger. The study is centered on thirty (30) holes selected to monitor the variation in the microbiological quality of the water. For that the parameters studied are total coliforms, faecal coliforms and E-coli. From these parameters is calculated the microbiological quality index (MQI) by Bovesse and Depelchin method 1980. The variations of the faecal contamination as well as those of the various parameters on the whole of the drillings are represented on maps of spatial distribution. On the whole of the drilling the (MQI), is zero which denotes the absence of any faecal contamination. On 96.67% of the holes is observed the presence of total sprouts with structures having a rate that exceeds 100 CFU per 100 ml of sample. The presence of total coliforms is also observed on 36.67% of the boreholes with structures presenting more than 100 CFU per 100ml of sample. Although these waters do not have faecal contamination, their microbiological quality does not meet the recommended standards for drinking water.

Changes in Sensory and Microbiological Quality Indices of Nile Tilapia (Oreochromis niloticus) and Grey Mullet (Mugil cephalus) During Ice Storage

Changes in Sensory and Microbiological Quality Indices of Nile Tilapia (Oreochromis niloticus) and Grey Mullet (Mugil cephalus) During Ice Storage

Assessment of surface water quality of Mencha River, Northeastern Algeria by index method

Mencha River is one of the largest river in the region of Jijel, Algeria. The human activities such as urban discharges, industrial, agricultural and livestock have significant effects on the quality of water. Because of its importance in the agricultural activities and dense population residing at its banks, the river faces several challenges from various anthropogenic activities. This situation exposes surface water to a severe pollution. The objectives of this study are to use different indexes to assess the current pollution status in Mencha River. Indexes used in this study were Organic Pollution Index (OPI) and Microbiological Quality Index (MQI). Based on the data collected throughout this study, results indicated that the upper reaches of the river (station 01) has had good water quality (OPI=4, MQI=4), while the station 04 presented a poor quality (OPI=2.75, MQI=2.33). Indeed, several pollution sources exist in this site. The agricultural activity, among different sources, was the strongest point in the downstream section of the river, as it contains high amounts of chemicals, causing major decrement in water quality. The used indexes also showed that at stations 02 and 03, the water quality was moderate (OPI=3.25, MQI=3). This study can be used to support the evaluation of regulatory and monitoring decisions.

Biogenic amine formation and distribution in Roumy cheese, an Egyptian-type hard cheese during the ripening period

Content of biogenic amines (BA) including tryptamine (Try), phenylethylamine (Phe), histamine (His), tyramine (Tye), putrescine (Put), cadaverine (Cad), spermidine (Sper) and spermine (Spr), chemical quality indices (amino nitrogen, AN; total volatile fatty acids, TVFF and malonaldehyde, MDA) and microbiological traits (total bacterial count, TBC; lactic acid bacteria, LAB and Molds/yeasts, M&Y) were evaluated within the ripening interval of 0- 24 weeks in Roumy cheese, an Egyptian-type hard cheese. The average concentrations of Try, Phe, His, Tye, Put, Cad, Sper, and Spr were recorded 1.89, 1.69, 2.02, 14.78, 1.92, 2.90, 0.54 and 0.42 mg/kg, respectively. With the elongation of ripening period, all of these amines were recorded and gradually increased by different ratios individually. At the end of ripening, after 24 weeks, Try, Phe, His, Tye, Put, Cad, Sper and Spr recorded 0.98, 88.90, 4.80, 511.89, 86.55, 26.34, 2.32 and 2.88 mg/kg, respectively. These represent increase of -48.15, 5157.53, 137.20, 3363.40, 4407.81, 808.28, 329.63 and 585.71% for these compounds above the baseline, respectively. The same behavioral was recorded for the chemical quality indices (AN, TVFF and MDA) and microbiological traits (TBC, LAB and M&Y). The distribution study indicated that substantially higher ( P < 0.01 ) contents of individual amines and the sum of BA were found in the outer-part samples in comparison with the core ones in the Roumy cheese samples. Also, the correlation analysis revealed that determination of chemical plus microbiological quality indices on the one hand and BA content on the other hand, gave the consistent results. In nutritional and toxicological point of view, Tyramine content increased linearly ( P < 0.01) with increasing time of ripening in Roumy cheese, and after 12 weeks of ripening (369.50 mg/kg) exceeded a toxicological limit (100 mg/kg of the consumed food). Individuals suffering from food intolerances and food allergies, and patients receiving monoaminoxidase (MAO) inhibitors, should avoid consumption of such ripened cheese. Key words: Biogenic amines, amino nitrogen, total volatile fatty acids, malonaldehyde , microbiological traits, outer-part, core, toxicological limit.

Lettuce quality loss under conditions that favor the wilting phenomenon

While temperature management is a usual accepted practice and is the simplest and easiest way of delaying vegetable deterioration, maintenance of the recommended relative humidity (RH) during postharvest storage is not always carried out. The objectives of this work were to simulate two RH conditions: optimal (95–98%) and low (70–72%) during the storage of lettuce heads at recommended temperatures (0–2 °C), and to address how deviation of RH from optimal conditions affects lettuce quality indices. The effects of storage on quality parameters were assayed as follows: weight loss and water content as physical indices, chlorophyll content as a greenness index, native microflora (mesophilic bacteria, psychrotrophic bacteria, lactic acid bacteria, total coliforms, yeast and molds) as microbiological quality indices, ascorbic acid retention as a nutritional quality index, and overall quality as a sensory acceptability index. Additionally, these indices (with the exception of weight loss) were analyzed in three lettuce sections: external (composed by outer and older leaves), middle (composed by mid leaves) and internal (composed by inner and younger leaves). Shelf-life of lettuce was significantly affected by RH. The exposure of lettuce heads to low RH drastically reduced shelf-life by 75%. Plants exposed to low RH had considerable weight loss from the first day to the end of storage. For both RHs, the middle and internal sections did not show chlorophyll changes during storage while the external section showed pigment degradation characterized by first order kinetics. Ascorbic acid underwent first order degradation for all situations (sections and RH conditions), but with different degradation rates. The microbial population counts were slightly affected by RH. The overall quality of lettuce stored at low RH decreased rapidly. The shelf-life of material stored at this relative humidity condition was 5 days, when the overall quality scores of middle and external sections were below the acceptability limit and only the internal section had a score above the limit. In addition, overall quality of lettuce stored at optimal RH decreased slowly. At day 5 of storage the three lettuce sections had high scores and the product was satisfactory. Only at day 20 did the external section show a score just on the acceptability limit.

Seasonal influence on microbial quality of water sources in some rural communities of Zaria, Nigeria.

This work examined fifteen (15) different water sources in some rural communities of Zaria, Nigeria for microbial index of water quality in relation to seasonal influence from June, 2005 to May, 2006. The microbiological quality indices indicated widespread fecal contamination with the on-set of rainy season Escherichia coli MPN-index indicated highly significant difference between seasons, stations, season by stations and year by stations (P

Relationship between the Agricultural Management of a Semi‐arid Soil and Microbiological Quality

The establishment of the incidence of different agricultural management practices on soil microbiological quality has become an issue of wide concern. This study was aimed to (i) determine the effect of different agricultural management practices (ecological, integrated, conventional, and conventional with the addition of pig slurry) on the microbial activity of a semi‐arid soil at two different stages (cropped and fallow) and (ii) adapt an existing quantitative method to assess the microbiological soil quality in the different management systems. Several microbial and biochemical parameters, as well as two water‐soluble carbon (C) fractions, were measured in the soil samples. Significant differences (P<0.05) were found between the different agricultural management systems for most of the microbiological parameters during the cropped period. Factorial analysis indicated that adenosine triphosphate (ATP), microbial biomass C, diphenol oxidase activity, urease activity, and water‐soluble carbohydrates had a high weight in factor 1. These parameters were selected to form part of the equation for calculating a microbiological quality index. During the cropped period, the ecological management yielded the highest score of the microbial quality index, whereas, during the fallow period, no differences were found among the index scores of the different agricultural management systems.

Multivariate study of the decontamination process as function of time, pressure and quantity of water used in washing stage after evisceration in poultry meat production

In poultry production, the washing stage takes place after the gutting stage. In the washing stage the carcasses are cleaned with pressurised water in order to remove any remains of blood, dirt and feathers on the skin, to reduce the superficial contamination, and to avoid subsequent drying in the freezers. This step is an important phase in the productive line because of its usefulness and its cost, since water is an expensive product and, sometimes, in short supply. Total Count, Pseudomonas, Enterobacteriaceae and Staphylococcus are microbial groups frequently analysed on carcasses in slaughterhouses. Their usefulness as index of microbiological quality can be assessed by means of univariate and multivariate statistical methods. In this study the influence of the washing stage on the superficial contamination of the chicken carcasses is shown with regard to the following factors: the water pressure, the amount of water and the length of the washing stage. It makes clear that multivariate statistics appears as a valuable tool for designing and implementing quality control systems, demonstrating that the contamination decreases significantly due to the effect of the washing stage and the water pressure. Time and amount of water variations do not affect the microbiological variables except for the Pseudomonas, which are affected by the amount of water and time variation but not by pressure variation.

Reliability of Several Microorganisms to Indicate the Presence of Salmonella in Natural Waters

A new index of microbiological quality of natural waters based on the coliphage test is proposed. Levels of coliphages corresponding to the concentrationgs of coliphages (Phgs) lower than 300 pfu/100 ml warrant a good microbial quality of waters affected with fecal pollution. In waters with industrial and domestic pollution Salmonella percentages higher than 5 % were detected even when this proposed index (Ph95) was applied. Thus the direct detection of the pathogen could be more useful in this case.

Presence of Indicator Organisms and Recovery of Salmonella in Fish and Shellfish

The efficacy of two methods for detection of Salmonella in 29 fish and 312 shellfish samples was evaluated, using replicate samples (100 g) of food homogenate. In method A, samples were preenriched 3 h in lactose broth, selectively enriched overnight in selenite cystine (35 C) and plated on brilliant green sulfa, xylose lysine desoxycholate and Hektoen enteric agar media. In method B, overnight nutrient broth cultures were enriched in tetrathionate brilliant green (43 C) and selenite cystine (35 C) broths and plated on brilliant green sulfa and bismuth sulfite agar media. Salmonella was recovered from seven (3%) shrimp samples of which six were detected by method B alone; the single positive sample detected by method A was negative by method B. Infected shrimp samples did not harbor coagulase-positive staphylococci, and aerobic plate counts ranged from 105 to 107 cells/g; two of the seven positive samples contained no detectable Escherichia coli. Our results suggest that short preenrichment incubation periods are not reliable and that tetrathionate brilliant green is superior to selenite cystine for effective recovery of Salmonella in shellfish. Coliforms are not reliable as an index of microbiological quality of fish and shellfish.

Microbiological Contamination of Cosmetics collected in Osaka Prefecture (1972-1977)

The microbiological quality of a variety of cosmetics, collected in Osaka Prefecture from 1972 to 1977, has been investigated.By this surveys, about 15% of 657 samples of unused cosmetics were found to be contaminated with bacteria and fungi.The most frequently contaminations in cosmetic products, were found in facial or hand creams (34% of 152 samples), liquid creams (21% of 42 samples), liquid shampoos (18% of samples) and hair lotions (15% of 46 samples), whereas we have rarely detected microbiological contamination less than 10% of the samples (which include hair sprays, hair tonics and facial or hand lotions).In these majority of cosmetic products contaminated with microorganisms, gram-possitive or gram-negative bacteria (which includes Bacillus, Micrococcus, and the like) and mold were mainly found as the lower microbiological counts (which not mostly exceed 1000 per gram or ml). But some specific bacteria (St. aureus, Ps. aeruginosa, E. coli and Coli-forms organisms) were not isolated from such contaminated cosmetics.In the view of these results, it is obvious that the total counts (in a low microbiological load) can be excellent index of micro-biological quality.