scholarly journals Biosynthesis and characterizations of extracellular enzymes of microbial isolates from dairy industrial effluent

2021 ◽  
Vol 23 (2) ◽  
pp. 121-134
Author(s):  
M. B. Osho ◽  
C. A. K Awe-Mathias ◽  
I. B. Onajobi

Diary effluents are environmental pollutant which could serve as source of substrate for microbial enzymes' synthesis. This research investigated the isolation and screening of bacteria and fungi with potential extracellular proteolytic and amylolytic properties from dairy effluents, and their characteristics for maximum enzyme production. Effluent from a dairy industry located in Ibadan, Nigeria, was collected for isolation and screening of microbial species for enzymatic activities. The Biological Oxygen Demand (BOD), Total Soluble Solid (TTS), and pH of the effluent were determined using standard procedures. The potential isolates were characterized morphologically and by molecular techniques. Proteolytic and amylolytic activities of isolates were investigated on skimmed milk starch agar respectively and optimized with varying pH (6.0 - 9.0), temperature (27 - 60 °C) and incubation period (12 - 72 h). Data were analyzed by Duncan Multiple Range Test. Biological Oxygen Demand, Total Soluble Solid and pH of the effluent were 14.67 mg/L, 13.33% and 7.58 respectively. Eleven isolates were positive for either protease or amylase synthesis, but only two showed both proteolytic and amylolytic activities and were molecularly characterized as Bacillus stratosphericus CM2HG6 and Aspergillus welwitschiae. Optimization showed that enzyme production by B. stratosphericus CM2HG6 was highest at 35 °C, pH 7.0 for 48 h, and that of A. welwitschiae achieved optimum production at 37 °C, pH 8.0 for 72 h. Under optimized conditions, Bacillus stratosphericus CM2HG6 was the highest amylase and protease producer (24.4 and 30.74 U/ml respectively), while A. welwitschiae was the lowest producer (12.58 and 18.8 U/ml respectively). The study successfully showed that these industrially-important enzymes can be produced by microbial strains isolated from dairy effluent, and production can be further optimized

2019 ◽  
Vol 14 (7) ◽  
pp. 649-657 ◽  
Author(s):  
Li Li ◽  
Jiemin Li ◽  
Jian Sun ◽  
Ping Yi ◽  
Changbao Li ◽  
...  

Background: Phospholipase D (PLD)is closely related to browning and senescence of postharvest longan fruit. Objective: This study investigated the effects of 2-butanol (a PLD inhibitor) on the expression and regulation of PLD during storage of longan fruit at a low temperature. Methods: Senescence-related quality indices showed that the 2-butanol-treated fruit presented lower pericarp browning index, pulp breakdown index and total soluble solid value than the untreated fruit. Results: The fruit treated by 60 µL/L 2-butanol exhibited the strongest inhibition on senescence, which significantly delayed changes in weight, titratable acidity content, total soluble solid content and ascorbic acid content. This treatment maintained a high level of total phenolic content and caused significant inhibition on pericarp browning and pulp breakdown. Through ELISA method, 60 µL/L 2-butanol treatment also reduced PLD activity. Real-time RT-PCR (RT-qPCR) results showed that PLD mRNA expression level was inhibited by 60 µL/L 2-butanol within 15 days. Western-blotting results further confirmed the differential expression of PLD during storage, and a relatively higher expression for PLD protein was found in control compared to the 2-butanoltreated fruit during 15-d storage. Conclusion: These results provided a scientific basis and reference to further investigating postharvest longan quality maintenance by regulating the PLD gene expression.


2021 ◽  
Vol 14 ◽  
pp. 117862212110281
Author(s):  
Ahmed S. Mahmoud ◽  
Nouran Y. Mohamed ◽  
Mohamed K. Mostafa ◽  
Mohamed S. Mahmoud

Tannery industrial effluent is one of the most difficult wastewater types since it contains a huge concentration of organic, oil, and chrome (Cr). This study successfully prepared and applied bimetallic Fe/Cu nanoparticles (Fe/Cu NPs) for chrome removal. In the beginning, the Fe/Cu NPs was equilibrated by pure aqueous chrome solution at different operating conditions (lab scale), then the nanomaterial was applied in semi full scale. The operating conditions indicated that Fe/Cu NPs was able to adsorb 68% and 33% of Cr for initial concentrations of 1 and 9 mg/L, respectively. The removal occurred at pH 3 using 0.6 g/L Fe/Cu dose, stirring rate 200 r/min, contact time 20 min, and constant temperature 20 ± 2ºC. Adsorption isotherm proved that the Khan model is the most appropriate model for Cr removal using Fe/Cu NPs with the minimum error sum of 0.199. According to khan, the maximum uptakes was 20.5 mg/g Cr. Kinetic results proved that Pseudo Second Order mechanism with the least possible error of 0.098 indicated that the adsorption mechanism is chemisorption. Response surface methodology (RSM) equation was developed with a significant p-value = 0 to label the relations between Cr removal and different experimental parameters. Artificial neural networks (ANNs) were performed with a structure of 5-4-1 and the achieved results indicated that the effect of the dose is the most dominated variable for Cr removal. Application of Fe/Cu NPs in real tannery wastewater showed its ability to degrade and disinfect organic and biological contaminants in addition to chrome adsorption. The reduction in chemical oxygen demand (COD), biological oxygen demand (BOD), total suspended solids (TSS), total phosphorus (TP), total nitrogen (TN), Cr, hydrogen sulfide (H2S), and oil reached 61.5%, 49.5%, 44.8%, 100%, 38.9%, 96.3%, 88.7%, and 29.4%, respectively.


2021 ◽  
Vol 9 (3) ◽  
pp. 611
Author(s):  
Zhendong Yang ◽  
Zhenghua Liu ◽  
Aleksandra Sklodowska ◽  
Marcin Musialowski ◽  
Tomasz Bajda ◽  
...  

Management of excessive aqueous sulfide is one of the most significant challenges of treating effluent after biological sulfate reduction for metal recovery from hydrometallurgical leachate. The main objective of this study was to characterize and verify the effectiveness of a sulfide-oxidizing bacterial (SOB) consortium isolated from post-mining wastes for sulfide removal from industrial leachate through elemental sulfur production. The isolated SOB has a complete sulfur-oxidizing metabolic system encoded by sox genes and is dominated by the Arcobacter genus. XRD analysis confirmed the presence of elemental sulfur in the collected sediment during cultivation of the SOB in synthetic medium under controlled physicochemical conditions. The growth yield after three days of cultivation reached ~2.34 gprotein/molsulfid, while approximately 84% of sulfide was transformed into elemental sulfur after 5 days of incubation. Verification of isolated SOB on the industrial effluent confirmed that it can be used for effective sulfide concentration reduction (~100% reduced from the initial 75.3 mg/L), but for complete leachate treatment (acceptable for discharged limits), bioaugmentation with other bacteria is required to ensure adequate reduction of chemical oxygen demand (COD).


2007 ◽  
Vol 6 (4) ◽  
pp. 515-519 ◽  
Author(s):  
Kazuo Takano ◽  
Tsuyoshi Kimura ◽  
Shogo Yamamoto ◽  
Shinichi Moritsugu ◽  
Goro Okamoto

2009 ◽  
Vol 30 (4) ◽  
pp. 329-336 ◽  
Author(s):  
Mia Kim ◽  
Moon Sik Hyun ◽  
Geoffrey M. Gadd ◽  
Gwang Tae Kim ◽  
Sang‐Joon Lee ◽  
...  

Author(s):  
R. Sandhiya ◽  
K. Sumaiya Begum ◽  
D. Charumathi

<p><strong>Objective: </strong>The objectives of the present study were a) to isolate and screen bacteria for dye removal from synthetic solution b) to optimize various variables such as pH, static/shaking and initial dye concentration on degradation of triphenyl methane dyes namely basic violet 3 and basic green 4 by isolated <em>Staphylococcus aureus</em> c) to analyse enzymes involved in the biodegradation of triphenylmethane dyes d) to treat real leather dyeing wastewater with newly isolated strain of <em>Staphylococcus aureus </em>e) to characterize untreated and treated leather dyeing wastewater f) to study the effects of real and treated effluent on plants and <em>Rhizobium</em>.<strong></strong></p><p><strong>Methods: </strong>Isolation of bacteria from sludge was carried out by spread plate method and the bacteria was identified by morphological and biochemical characterization. The isolated bacterium was screened for dye decolorization potential of triphenylmethane dyes basic violet 3 and basic green 4 The effects of parameters were studied by varying pH (from 3 to 9), temperature (from 15-45 °C), and initial dye concentration (from 10-500 mg/l). The enzyme involved in biodegradation was studied in intracellular extract. Real leather dyeing wastewater was treated with the bacteria and characterized. The treated wastewater was tested on plants and <em>Rhizobium </em>for toxicity. <strong></strong></p><p><strong>Results: </strong>Dye decolorization potential of bacteria <em>Staphylococcus aureus</em> isolated from wastewater for leather dyes basic violet 3 and basic green 4 were evaluated. Dye decolorization using bacteria was found to be dependent on physicochemical parameters (shaking, pH and initial dye concentration). Enzymes NADH-DCIP reductase and MG reductase were found to play dominant role during biodegradation of synthetic dyes. Application oriented studies using growing bacteria in pure cultures were carried out with leather dyeing wastewater collected from DKS prime tanners. Analysis of raw leather dyeing wastewater showed high pollution load in terms of color, Total solids, Total suspended solids, Total dissolved solids and Biological oxygen demand whereas the leather dyeing wastewater treated with pure culture of <em>Staphylococcus aureus</em> showed considerable decrease in Total solids, Total suspended solids, Total dissolved solids and Biological oxygen demand values which were within the permissible limits. Phytotoxicity and microbial toxicity studies confirmed the non-toxic nature of treated leather dyeing wastewater. <strong></strong></p><p><strong>Conclusion: </strong>Our study proved that <em>Staphylococcus aureus</em> can serve as a potential remediation agent for the treatment of leather dyeing wastewater.</p>


2012 ◽  
Vol 8 ◽  
pp. 44-47
Author(s):  
Ghazal Nosheen ◽  
Muhammad Ullah ◽  
Kashif Ahmad Khan ◽  
Attiq Ur Rehman

The disposal of untreated industrial effluent into receiving water courses has become a major environmental challenge being faced by most of the developing countries. The high-strength and toxic wastes are responsible for a variety of water-borne diseases. In Pakistan numerous industrial units that dispose their effluent directly into receiving stream without any treatment. This study was, therefor designed to assess the wastewater characteristics of some major industrial units in the surrounding area of River Kabul, which is one of the most signifi cant resources of water in the north region of the country.The main objectives of this study were to evaluate the wastewater characteristics of some major industrial units in terms of BOD (Biochemical Oxygen Demand), COD (Chemical Oxygen Demand), and TSS (Total Suspended Solids) etc. For this purpose, various representative samples were collected from the major industrial units like sugar, paper, ghee (Butter) and textile mills, and were analyzed using standard laboratory techniques. The results indicates that the BOD of sugar, paper, ghee (butter) and textile mills is in the range of 2235mg/L, 1150mg/L, 844mg/L and 745mg/L, respectively. Whereas, the COD of sugar, paper, ghee and textile mills was noticed to be 3945mg/L 2045mg/L, 2240mg/L and 1244mg/L respectively. Owing to the disposal of such highstrength wastes water without treatment, a remarkable increase in the TSS from 96 to 382mg/L, and decrease in DO (Dissolved Oxygen) concentration from 8.8 to 6.7mg/L of River Kabul was observed. The results of this study suggest that all the wastewater coming from the industrial sources should be properly treated as an integral part of their production before their fi nal disposal into River Kabul to secure its natural water quality.DOI: http://dx.doi.org/10.3126/hn.v8i0.4924Hydro Nepal: Journal of Water, Energy and Environment Issue No. 8, 2011 JanuaryPage: 44-47Uploaded date: 23 June, 2011


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