Higher Microbial Population Research Articles

Review of Different Composting Methods towards End Product Quality, Cost of Production, Process Adoptability Potential, Post Soil Application Efficacy and GHG Mitigation Potential Fundamental Factors Behind Attending Objectivities of any Regenerative Far

The impacts of climate change on crop productivity and the emerging challenges towards food security have led to the introduction of the regenerative farming approach, which considers regeneration of soil as a prime criterion for sustained food production. Currently, compost is considered as the key component for soil rejuvenation or, more precisely, soil microbial rejuvenation. This is because high-quality compost is the most economical source of diverse microflora. Within the scope of the present study, we reviewed the different composting methods used in large scales in the different Indian tea estates; as per the five-point criteria of end product quality, cost of production, process adoptability potential, post-soil application efficacy and GHG mitigation potential. In the comparative study, the process adoptability potential was greater for Novcom compost (9.97), which could be primarily due to the shortest biodegradation period, non-selectivity of the raw materials and non-dependency on the infrastructural requirements. The compost quality index (CQI) value was also significantly greater in the case of the Novcom compost (CQI: 5.75) than for Vermi compost (CQI: 2.4) and FYM/Heap compost (CQI: 1.75), which could be due to the presence of a very high microbial population (1016 cfu per g moist compost; or at least 10,000 times greater than that of the other compost) in the Novcom compost. A there year comparative study regarding post soil effectiveness in terms of crop productivity and soil quality development was performed under the FAO-CFC-TBI project in the Maud tea estate, which revealed higher crop productivity (30.75% higher than that of the control and approximately 11% higher than that of the Vermi & FYM/Heap compost applied plots) and a better value cost ratio under the Novcom compost applied plots. The soil quality enrichment was measured through the soil development index (SDI), which revealed more than 55% higher impact in the Novcom compost applied plots than in the other plots, which was mainly contributed by the increase in the soil microbial population. Comparative cost analysis on the basis of present material and manday costs revealed that Novcom compost was the most economical (Rs 2345/ton), followed by FYM/Heap compost (Rs 3245/ton) and Vermi compost (Rs 5395/ton), indicating that the Novcom composting method was 60% less expensive than the Vermi composting method. Most importantly, a comparative study of soil carbon sequestration and GHG mitigation potential under different composting methods evaluated via the IPCC methodology and Century model simulation of EPA revealed the highest soil carbon sequestration potential under Novcom compost (152.9 kg CO2e/ton raw material), followed by FYM/heap compost (69.5 kg CO2e/ton raw material) and Vermi compost (66 kg CO2e/ton raw material). Finally, a comparative study of GHG mitigation potential revealed that Novcom compost was much greater than other composting methods, with a value of 508 kg CO2e/per ton raw material, whereas the nearest value was in the case of Vermi compost, with a value of 277 kg CO2e/per ton raw material. This was due to the shorter biodegradation period and greater microbial population in the Novcom compost, leading to greater scoring in terms of process efficiency and soil carbon sequestration potential. Thus, for any GHG mitigation program, Novcom composting Technology could be a natural choice for sustainable soil management.

Unraveling the impact of high arsenic, fluoride and microbial population in community tubewell water around coal mines in a semiarid region: Insight from health hazards, and geographic information systems

High arsenic (As), fluoride (F-), and microbial pathogens coexist in semiarid conditions afflicting > 240 million people worldwide including Pakistan. Groundwater quality has declined due to geogenic and manmade activities providing suitable ground for ubiquity, bioavailability, and toxicity of contaminants. We tested the health hazard, distribution, and apportionment of As, F-, and microbes in groundwater around coal mines in Quetta, Pakistan. The range of As, and F- concentrations in groundwater were 0.2–16.6 µg/L, 0.4–18.5 mg/L. Both, As and F- correlate with high HCO3-, pH, Na+, SO42-, Fe, and Mn, and negatively with Ca2+ water. The coalfield showed many folds higher As 15.8–28.5 µg/L, and F- 10.8–34.5 mg/L compared to groundwater-wells. Geochemical phases revealed saturation of groundwater with calcite, dolomite, fluorite, gypsum, and undersaturation with halite-mirabilite, and arsenopyrite minerals. The positive matrix factorization (PMF) model assessed five-factor solutions: geogenic, industrial, coal mining, sulfide & fluoride-bearing mineral-dissolution, and agriculture pollution delivered As, F-, and microbial contamination. About 24.6 % and 64.4 % of groundwater samples exceeded the WHO guidelines of As 10 µg/L, F- 1.5 mg/L. The carcinogenicity, and non-carcinogenicity of As, and F- were higher in children than adults. Therefore, health hazards in children are of great concern in achieving sustainable management goals.

PERFORMANCE, ORGAN DEVELOPMENT AND ILEAL MICROBIAL POPULATION OF BROILER CHICKS FED HIGH QUALITY CASSAVA PEEL (HQCP) SUPPLEMENTED WITH YEAST

Ninety-six (96) day old Ross 308 chicks were used to investigate the effect of High-Quality Cassava Peel (HQCP) diet supplemented with yeast; on their performance, organ measurement and ileal microbial population at 0-3 weeks. The chicks were randomly allocated to four dietary treatments with three replicates each. Treatment 1 had 0 % HQCP and 0g yeast Treatment 2 had 0 %HQCP and 0.1% yeast, Treatment 3 had 15.12 % HQCP and 0% yeast, and Treatment 4 was 15.12% HQCP and 0.1% yeast. Treatment 3 and 4 had HQCP levels to replace 28% of the maize content in the control diet (Treatment 1). The result showed that there was a significant difference (p<0.005) in feed intake, body weight gain, feed conversion ratio (FCR) and organ measurement but none (p>0.005) on ileal microbial population. Birds fed T1 and T3 diets had the highest feed intake, 5.10kg and 4.27kg, respectively while birds fed T1 and T4 had highest body weight gain (4.97kg and 4.13kg, respectively). Lowest FCR (0.84) was recorded for birds fed HQCP and 0.1g of yeast, same birds also had highest microbial population (101,000 cfu). Birds fed HQCP and yeast benefited from the yeast supplementation at 0-3 weeks.

Tillage and Seaweed Extract Effects on Soil Physio-chemical Properties, Microbial Population and Yield of Sweet Corn (Zea mays saccharata L.) in Hills of Nagaland

Background: Sweet corn is a selectively crossbred variant of maize designed with the intention of enhancing its sugar content. It highly remunerative and is gaining momentum among the progressive farmers due to its extra sweetness, early maturity, nutritious green fodder at harvest which earns high market value. Methods: Field experiments were undertaken during kharif season of 2021 and 2022 at Experimental Research Farm, Department of Agronomy, SAS, Nagaland University to access tillage and seaweed extract effects on soil physio-chemical properties, microbial population and yield of sweet corn. Result: The results from study revealed that yield parameters such as green cob yield, green fodder yield showed significant increase under conventional tillage and application of 10% S-SWE. Highest microbial population was exhibited under zero tilled plots, Sargassum seaweed extract (15% S-SWE) application noted significantly higher bacterial, actinomycetes and total microbial population.

Impact of Humic Acid-Based Bio-stimulant ‘Humetsu’ on Growth and Yield Attributes of Potato (Solanum tuberosum L.)

Aims: The current study was carried out to examine the impact of humic-acid-based bio-stimulant (liquid formulation) ‘Humetsu’ on growth and yield attributes of potato variety Kufri Chipsona-4. Study Design: The study used a Randomized Block Design with 3 replications and 8 treatments. Place and Duration of Study: The existing experiment was worked out at Teaching Farm, College of Agriculture under BCKV, Burdwan Sadar during Rabi, 2019-20 and Rabi, 2020-21. Methodology: The test product humic-acid based bio-stimulant (liquid formulation) ‘Humetsu’ was used for seed treatment at the rate of 5 ml/kg tuber before sowing of potato and 2.5 ml /L water was sprayed treatment-wise as per protocol using a water volume of 500 liters per ha with knapsack sprayer fitted with flat fan deflector nozzle in potato. Results: The results elucidated that significantly maximum plant emergence, number of branches per plant and increased available N, P, K and Organic carbon (OC) in both years were recorded in treatment T4 (100% NPK + 3 application of ‘Humetsu’ (Seed treatment at the rate of 5 ml/kg of tuber and 2 foliar sprays at the rate 2.5ml L-1 water at 30 DAS & 55 DAS). The highest plant height, TSS (%), and fewer days to harvest were found in treatment T7 (80% NPK + 3 application of ‘Humetsu’ (Seed treatment at the rate 5ml/kg of tuber and 2 foliar sprays at the rate 2.5ml L-1 water at 30 DAS & 55 DAS) followed by treatment T4, T5, and T6. The maximum number of tubers per plant, total tuber yield, and marketable tuber yield were noticed in the treatment T7 during both years. The highest microbial population in the soil was noticed in the T7 during both the years. On the other hand, the least plant height, TSS (%), plant emergence, number of tubers per plant, total tuber yield, marketable yield per ha, more days to harvest, and the least microbial population in soil were observed in (control) treatment (T8) during both the years. Conclusion: Application of 80% NPK + 3 application of ‘Humetsu’ (Seed treatment at the rate 5ml/kg of tuber and 2 foliar sprays at the rate 2.5ml l-1 water at 30 DAS& 55 DAS) has a significant impact in yield of potato with 20% reduction of the recommended dose of NPK fertilizers.

Effect of soil nutrient management and land configuration on rhizospheric microbial diversity under cotton (Gossypium spp.)-wheat (Triticum aestivum) cropping system in semi-arid region

Microbial diversities in the vicinity of root rhizosphere play a crucial role in promoting plant and soil ecosystem health and productivity. They have great potential as key indicators of soil health in agro-ecosystems enhancing the availability of nutrients. Therefore, a study was carried out during 2019–20 and 2020–21 at research farm of Chaudhary Charan Singh Haryana Agricultural University, Hisar, Haryana to investigate the rhizospheric microbial diversities under cotton (Gossypium spp.)-wheat (Triticum aestivum L.) cropping system as affected by land configuration and nutrient management. Experiment consisted of 5 nutrient treatments replicated thrice and two land configurations, viz. raised bed (RB) and flatbed (FB) planned in factorial randomized block design (RBD). The results of experiment under RB revealed that farmyard manure (FYM) and FYM with biofertilizer and cow urine formulation (FYM + Org) showed the highest bacterial, fungal, phosphate solubilizing bacteria, azotobacter and actinomycetes population (6.92 to 7.51, 24.63 to 26.80, 7.61 to 7.68, 8.74 to 9.15,7.27 to 7.66 cfu/g soil, respectively). The decrease in microbial diversity was observed under inorganic fertilizer application through soil test crop response approach with targeted yield of 5.5 and 2.8 mg/ha (STCR5.5/2.8) and 6.0 and 3.2 mg/ha (STCR6.0/3.2) and control for cotton and wheat, respectively. Higher microbial population and soil organic carbon was found in RB compared to FB. The STCR5.5/2.8 and STCR6.0/3.2 recorded highest cotton and wheat yield followed by FYM and FYM+Org and least in control under cotton-wheat system. Thus, the study suggests that RB planting with an addition of manures along with biofertilizer and cow urine formulation could be a sustainable and feasible practice through enhanced microbial population raising soil fertility leading to increase the crop yields under semi-arid regions.

Evaluation of Physicochemical Properties of Yogurt Fortified with Four Verities of Common Bean Whey (Phaseolus vulgaris)

Background: In recent years, the role of novel foods in public health has rapidly grown due to increased life expectancy, rising medication costs and consumers’ focus on obtaining health benefits. Methods: This study evaluates the acid production, microbial growth, physicochemical and textural properties of common bean-fortified yogurt (CBWFY) during 28 days of cold storage. Result: All varieties of CBWFY showed higher acidity and lower pH value, resulting in a higher microbial population after production and during 28-day storage. The color values “a” and “L” did not vary significantly in all samples and remained steady after 28 days, while the “b” value increased. The highest syneresis (14.86%) was found in white bean whey, while the lowest syneresis (1.81%) was observed in kidney bean whey. In terms of texture, the cohesiveness of CBWFY and the control sample decreased, while the hardness, springiness and gumminess improved during cold storage. Remarkably, cranberry bean whey had higher values (cohesiveness, springiness and gumminess) despite the hardness found in white bean whey.

Safety and quality attributes of fresh sardines (Sardina pilchardus) in storage scenarios imitating harvest‐to‐refrigerator conditions

SummaryThe effect of initial storage temperature on the quality and safety characteristics of sardines was investigated. Initially, fresh sardines were stored in aerobic conditions at 0 °C, 5 °C or 10 °C for 24 h and subsequently, they were vacuum packed and stored at two distinct temperatures, namely 4 °C and 8 °C. Microbial growth, lipid oxidation (TBA values), pH, total volatile basic nitrogen (TVB‐N) and biogenic amines concentrations were monitored throughout storage. There were no notable differences in the pH levels of the different treatments, whereas higher TBA and TVBN values were observed for the sardines initially stored at higher temperatures. Significant differences (P < 0.05) in biogenic amine concentrations were observed throughout storage time. Samples exposed to lower initial temperatures exhibited longer lag times and lower production rates of biogenic amines. There were no statistically significant differences observed in microbial populations, although the sardine samples stored at 10 °C initially had the highest microbial populations. These results support the conclusion that initial handling conditions are important for the shelf‐life of fresh sardines and can drastically affect their overall quality and safety.

Nutritional content and microbial contamination of fresh cold and frozen Bali beef in Mambal RPH production in Badung Regency, Bali Province

This study aims to determine the nutrition and microbial contamination of fresh, chilled, and frozen Bali beef. This study used a completely randomized design (CRD) direct pattern a 3x7, with 3 treatments and 7 repetitions of Bali beef. The treatments were: (P1) meat stored at room temperature (27°C-35°C) for less than 1 day (fresh meat), (P2) meat stored at 0°C-4°C for 1 day -2 days (cold meat), (P3) meat stored at a minimum temperature of -18°C with a storage time of 1-7 days (frozen meat). The variables observed in this study were the nutritional content of meat, namely water content, protein, fat, ash and carbohydrates as well as pathogenic bacterial contamination, namely Total Plate Count (TPC), Colliform and E-Colli. The results of this study showed that the nutritional content of water content and ash content in fresh, chilled and frozen meat had no significant effect. However, the protein content decreased significantly when the meat was frozen. The fat and carbohydrate content had the opposite result, namely, there was a significant increase when the meat was frozen. In terms of meat microbiological contamination on TPC, Coliform and E-colli variables, showed that frozen meat had the highest microbial population followed by fresh meat and cold meat had the lowest total pathogenic microbes.

Short Communication: The potential of soil microbes in the three kerangas forest ecosystems on Belitung Island, Indonesia

Abstract. Oktavia D, Pratiwi SD, Pratiwi D, Kamaludin NN. 2023. Short Communication: The potential of soil microbes in the three kerangas forest ecosystems on Belitung Island, Indonesia. Biodiversitas 24: 1895-1899. The biogeochemical cycles on Earth are governed by living creatures, therefore the composition and activity of microbial communities are important ecological issues. In this study, we investigated the abundance of soil microbes randomly existing from the three types of kerangas forest ecosystems (Bukit Peramun, Cendil Kerangas Forest, and Gunung Lumut) in Belitung Island which belongs to the Geosites of Belitong UNESCO Global Geopark. In comparison to the Bukit Peramun and Hutan Cendil habitats, the populations of bacteria and fungus in the Gunung Lumut were greater at 3.11 x 1010 and 1.14 x 105 cfu g-1, respectively. In Gunung Lumut, there was a comparatively high population of soil bacteria. Gunung Lumut is a site where a variety of mosses have taken over and are overpowered by the terrain due to its high humidity and weathered rocks. Generally, under various conditions, a specific function is more likely to be carried out by soils with higher microbial populations. Understanding soil health and agricultural productivity depends on an understanding of the presence of soil bacteria in various types of kerangas forests. Our study aids the Geosites of the Belitong UNESCO World Geopark in ensuring a long-term sustainable ecosystem.

Caracterização microbiológica de duas espécies de peixes neotropicais oriundas de área quilombola maranhense, Brasil

The aim of study is to feature the microbiological quality of two neotropical fish species from the quilombola area of Maranhão State, Brazil. In order to do so, 21 samples of Hoplerythrinus unitaeniatus and 21 samples of Cichlasoma bimaculatum were captured in flooded environment. Collected fish were euthanized in laboratory environment; muscle fragments were removed for microbiological analyses focused on enumerating molds and yeasts, viable strict and facultative mesophilic microorganisms and coagulase-positive staphylococci; on counting total and thermotolerant coliforms; and on investigating Escherichia coli and Salmonella sp. Microbiological results were compared to the Brazilian legislation, which establishes the list of microbiological standards for food products. Among the assessed fish, 9.52% were classified as non-acceptable for human consumption, based on the Salmonella parameter. Enumerated coagulase-positive staphylococci ranged from < 10 to 3.9 x 104 CFU/g; 9.52% of assessed fish were classified as having intermediate standard for human consumption, whereas 4.76% were classified as non-acceptable for such a purpose. E. coli counting ranged from 3.6 to > 1,100MPN/g; 4.76% of assessed fish were classified as having intermediate standard for human consumption, whereas 4.76% were classified as non-acceptable for such a purpose. Total and thermotolerant coliforms’ counting and the enumeration of viable strict and facultative aerobic microorganisms, as well as of molds and yeasts, have evidenced high microbial population rates; this finding suggests poor hygienic conditions at capture site, contaminated raw material and risk of incidence of enteropathogens. This finding has evidenced imbalance in the investigated environment, as well as compromised aquatic biodiversity.

Effect of Integrated Weed Management Practices on Microbial Population in Soil, Yield and Economics in Wet Direct Seeded Rice

An experiment had been conducted at the Agronomy Farm, Indira Gandhi Krishi Vishwavidyalaya, Raipur, (C.G.) in the kharif season of 2019, to determine the effects of integrated weed management practices on microbial population in soil, yield and economics in wet direct seeded rice. Pre-emergence herbicides (Oxadiargyl and Pretilachlor) were followed by post-emergence herbicide (Bispyribac-Na), mechanical and manual weeding. Plots treated with oxadiargyl performed better than pretilachlor. When Oxadiargyl was integrated with Hand Weeding (HW) at 35 days after sowing (DAS) gave results which were better than twice HW plot (T10). Oxadiargyl @ 70g/ha at 7-11 DAS fb HW at 30-35 DAS (T4) proved to be superior over all the treatments when yield and economics of wet direct seeded rice was concerned and was statistically at par with twice HW plot (T10) and oxadiargyl @ 70 g/ha at 7-11 DAS fb bispyribac-Na @ 25 g/ha at 30-35 DAS (T2). The unsprayed and two-hand weeding treatments had much lower levels of fungi, actinobacteria, and bacteria than the other weed control methods. The herbicidal treatments had much higher microbial populations at all stages of observation.

Variation in soil organic carbon content and its dynamics under different cropping sequences and nutrient management practices in middle indo-gangetic plains

In the era when the population is escalating at a rapid rate while on other hand the land for cultivation is declining, there is tremendous pressure in high fertile lands like the Indo-Gangetic plains to produce food grains with intensified cropping. This intensification of agriculture has lead to stagnation of yield in cropping systems due to decline in soil organic matter and nutrient cycling. Soil organic carbon along with the microbial biomass are important indicators of physical, chemical as well as biological properties. This two parameters can be determined by various methods like dehydrogenase activity, soil respiration rate and microbial biomass calculation by chloroform and irradiation method. The current paper comprises of the study of different cropping systems in the Indo Gangetic plains in order to analyze its different organic carbon pool, relationship between them and different land use system that influences them. It was noticed that the system receiving both organic and inorganic fertilizers had higher total organic carbon, higher respiration rate, labile carbon along with higher microbial population. Under the nutrient management consisting of FYM + NPK fertilizer treatment there was increasing microbial biomass carbon and total organic carbon over other treatments because of more or higher root biomass. Therefore for a healthy soil and sustainable production system in high fertile and demand area of Indo Gangetic plain it is necessary to assess the soil organic carbon pools and maintain them by using integrated nutrient management.

INFLUENCE OF FOLIAR SPRAY OF BIO-INOCULANT AND MICRONUTRIENT ON SOIL BIOLOGY AND YIELD IN BROCCOLI

The experiment was carried out in the years 2021-22, at the Department of Agricultural Microbiology, Indira Gandhi Krishi Vishwavidyalaya, Raipur (Chhattisgarh). The study involved application of foliar spray of bio-inoculants and micronutrient; Ammonium Molybdate. Bio-inoculants; Azotobacter and Azospirillum inoculation strains were collected from Microbiology repository and were revived for biochemical characteristics on Jensen’s and Okon’s media respectively. Both the isolates showed positive reaction for starch hydrolysis test, catalase test, urease test and oxidase test. Plant parameters evaluated include biomass accumulation and fruit weight per plant. The experimental results revealed that significantly maximum fruit weight per plant (359.0g), dry shoot biomass (16.6g/ plant), dry root biomass (8.6g/ plant) were recorded under T4 (IF + Foliar Application of Bio-inoculants and Ammonium molybdate 0.2%). Besides higher microbial population, Azotobacter (44.3 x 103 cfu/ g of soil), Azospirillum (28.5x 103 cfu/ g of soil) were also observed to be significant under T4. Dehydrogenase activity in rhizosphere soils was found maximum 27.3 µg TPF/g soil/h under T4 (IF + Foliar Application of Bio-inoculants and Ammonium molybdate 0.2%) at 60DAT. Thus application of Bio-inoculants along with Ammonium molybdate (0.2%) as foliar spray along with 50% inorganic fertilizer proved to be the most effective and may be adopted in Broccoli cultivation.

Anticipated atmospheric CO2 elevation differentially influenced the soil microbial diversities in crop, grassland, and forest: A meta-analysis

The increasing of atmospheric carbon dioxide (CO2) has a greater impact on soil microbial diversity and related soil nutrient dynamics under different ecology. In our study, a global database of 572 observations from 202 research publications analysed to explore the impacts of increased atmospheric CO2 on soil microbial diversities. The soil microbial biomass carbon (MBC), structural (microbial populations), and functional (enzymatic activities) microbial diversities were analysed across 22 nations and 108 crops (including forest, grassland and C3 plants). The impact of three elevated CO2 (eCO2) concentrations i.e., <25%, 25–50% and >50% over ambient in three-time scale (1970–1989, 1990–2009 and 2010–2020) and two region (tropical and temperate) on the above parameters were studied. Higher MBC contents were found under eCO2 level (>50%) followed by eCO2 level 25–50% and <25% over ambient in C3 plants and forest ecology, however, in grassland the average MBC content was higher under eCO2 level 25–50%. Soil enzymatic activities were higher under eCO2 (25–50%) than other elevated CO2 conditions in the forest and C3 plants, whereas in grasslands, the enzymatic activities decreased with an increase in CO2 concentrations. These findings suggested that grassland was more sensitive to elevated CO2 as such compared to the forest and C3 plants. Both the bacterial and fungal populations were higher only up to eCO2 level (25–50% over ambient) in all the vegetations. So, higher microbial populations and soil enzymatic activities were noticed up to 50% elevation of CO2 over ambient conditions irrespective of the vegetation and region indicating higher belowground soil activities. Therefore, the findings suggested that there would be higher belowground soil activities in increased CO2 levels (anticipated climate change scenario) in agriculture and forest crop up to a certain threshold elevation of CO2 which needs better water and nutrient management for getting sustainable yield. The finding also suggested region and vegetation-specific (crop/forest/grassland) management options are necessary for fetching advantage of CO2 fertilization and to tackle the abiotic stress management of crops.

Raw goat's milk fermented Anbaris from Lebanon: insights into the microbial dynamics and chemical changes occurring during artisanal production, with a focus on yeasts.

Anbaris is a raw goat milk product naturally fermented in terracotta jars. The aim of this research paper was to follow the dynamics underlying an artisanal production to understand the concomitant evolution of the microbial populations in relation to the chemical changes occurring within the product, make sure of the sanitary conditions prevailing during the production and uncover for the first time its culturable yeast populations. Throughout the fermentation process, Anbaris was endowed with high acidity and included high microbial populations counts of LAB and yeasts that were rapidly installed within the product and maintained as regular new milk additions were made, contributing to lipolytic and proteolytic activities. Salt content varied according to the arbitrary salt additions made during the process but was high in the end product while protein and fat contents varied inversely to moisture. Frequent additions of Enterobacteriaceae and Coliforms contaminated milk samples seemingly fueled a contamination of the product during its manufacturing and in the final fresh Anbaris. Seven species of culturable yeasts, Pichia kudriavzevii, Kluyveromyces marxianus, Rhodotorula mucilaginosa, Saccharomyces cerevisiae, Debaryomyces hansenii, Candida parapsilosis and Kazachstania exigua were found during the production. The first two dominated the process in terms of frequency of occurrence and abundance at the different stages and might be signature species of the product. The same lineage of K. marxianus isolates was maintained throughout the fermentation and sample specific patterns were observed. Strains of this species exhibited low diversity within our product, and more globally in the Lebanese dairy products we studied.

Microbial-based detonation and processing of vegetable waste for high quality compost production at low temperatures

Composting is a resourceful and harmless technique for reducing vegetable waste (VW), but low temperatures limit the efficiency and quality of composting. Owing to the perishability of the VW and its high indigenous microbial populations, the development of microbial inoculants to enhance its composting is challenging, and thus rarely reported. This study proposed a method for screening and applying compost inoculants to improve the efficiency, safety, and maturity of VW composting at low-temperature. Five cold-adapted (10 °C) strains (Brachybacterium, Klebsiella, Myroides, and Proteus) with glycolytic, starch-hydrolytic, and pectin-degrading functions and four heat-adapted (60 °C) strains (two Parageobacillus and two Bacillus strains) with cellulose-degrading function were screened and inoculated before the initial and thermophilic period of composting, respectively. The inoculants (group T) raised the average temperature of the thermophilic period by more than 2 °C. During the cooling period, the germination index in the T group was 104.7% as compared to 83.3% in the control group. Initially added weed seeds and pathogens were inactivated in both groups, but the rate of inactivation was faster in the T group. The ratio of humic acid to fulvic acid was 2.2 in the T group during the cooling period as compared to 1.4 in the control group, which represented a significant increase (62.0%) in this conversion. During the thermophilic or cooling period of the composting, the inoculants significantly increased the cellulase activity by 74.9%, urease activity by 19.7%, protease activity by 18.6% and catalase activity by 24.4–43.5%. The inoculants not only enhanced enzymatic activities but also restructured and optimized the microbial communities, especially the composition of fungal communities. Moreover, inoculants improved microbial interactions and the contribution of fungi in the composting process. This study provides a theoretical basis and practical knowledge regarding the screening and application of inoculants for performing low-temperature VW composting. Our research could open new avenues of basic and applied research in the science of composting to utilize vegetable wastes for sustainable agriculture and a clean environment.

Physiochemical and Microbial Analysis of Wastewater from Food Industry Effluent near Kuthrel area, Durg District, Chhattisgarh

Abstract: Physiochemical analysis of waste water effluent of food industry has been an intriguing subject in recent years because of issues related to water pollution. Industrial effluent discharge act as one of the major factor that contributes water pollution. Since literatures mentioning physiochemical profile of food industries effluent from Chhattisgarh origin were few. The present study intends to study physico-chemical parameters and microbial analysis of waste water of food industry effluent near kuthrel area from durg district. Results revealed slightly basic nature of the effluent. Value of Dissolved Oxygen (DO) was low whereas, high TDS and COD values were observed suggesting high amount of organic matter present in the effluent. BOD level was under the standard discharge range according to Central Pollution Control Board (CPCB). However microbial analysis of effluent indicated high microbial population with gram negative bacteria and some fungal species which suggests that the effluent must need more adequate and proper treatment before its discharge to reduce microbial load so as to prevent contamination of water bodies into which the effluent might get discharged. Keywords: Effluent, food industry, physiochemical parameters, microbial analysis, rural area

Effect of Operating Parameters and Energy Expenditure on the Biological Performance of Rotating Biological Contactor for Wastewater Treatment

The rotating biological contactor (RBC) is resistant to toxic chemical and shock loadings, and this results in significant organic and nutrient removal efficiencies. The RBC system offers a low-energy footprint and saves up to 90% in energy costs. Due to the system’s low-energy demand, it is easily operable with renewable energy sources, either solar or wind power. An RBC was employed to degrade pollutants in domestic wastewater through biodegradation mechanisms in this study. The high microbial population in the RBC bioreactor produced excellent biological treatment capacity and higher effluent quality. The results showed that the RBC bioreactor achieved an average removal efficiency of 73.9% of chemical oxygen demand (COD), 38.3% of total nitrogen (TN), 95.6% of ammonium, and 78.9% of turbidity. Investigation of operational parameters, disk rotational speed, HRT, and SRT, showed the biological performance impact. Disk rotational speed showed uniform effluent quality at 30–40 rpm, while higher values of disk rotational speed (&gt;40 rpm) resulted in lower effluent quality in COD, TN, and turbidity. The longer hydraulic retention time and sludge retention time (SRT) facilitated higher biological performance efficiency. The longer SRTs enabled the higher TN removal efficiency because of the higher quantity of microbial biomass retention. The longer SRT also resulted in efficient sludge-settling properties and reduced volume of sludge production. The energy evaluation of the RBC bioreactor showed that it consumed only 0.14 kWh/m3, which is significantly lower than the conventional treatment methods; therefore, it is easily operable with renewable energy sources. The RBC is promising substitute for traditional suspended growth processes as higher microbial activity, lower operational and maintenance costs, and lower carbon foot print enhanced the biological performance, which aligns with the stipulations of ecological evolution and environment-friendly treatment.

Reconnaissance study of air quality in traffic tunnels: A case study of Aba-Saleh Al-Mahdi tunnel, Iran

Traffic tunnels have the potential to reduce the traffic congestion, but in some cases, they lead to the accumulation of air pollutants. The present study focused on the analysis of chemical and biological pollutants inside and outside of the largest tunnel in Iran. The measurements were done during different hours and days in four seasons (2018–2019). The collected data showed that the inside of the tunnel was more polluted than the outside, and the type, the number of passing cars and the weather condition had an effect on concentrations. Winter, summer and evenings are the most polluted periods. Comparison of data with national and WHO standards revealed that SO2 is a critical pollutant for all periods; NO2 is a problem during summer, winter and evenings. The concentration of PM2.5 exceeded these standards in the evenings. A high correlation between PM2.5 and PM10, in concentration, changes and spatial distribution points to the same emission sources. For biological pollutants, a high microbial population was found during the summer and afternoons. Among the isolated Gram-positive bacterium, the Bacillus sp (38%) and Aspergillus sp (32%) were the highest population of bacteria and fungi, respectively. Measurement results in combination with a high rate of hospital admissions emphasized the poor air quality inside the tunnel and the necessity for the installation of mechanical ventilation systems.