Production of antihypertensive and antioxidant activities by enzymatic hydrolysis of protein concentrates recovered by ultrafiltration from cuttlefish processing wastewaters

This work focuses on the production of antihypertensive and antioxidant activities using enzymatic hydrolysis of protein concentrates recovered by ultrafiltration of different wastewaters from the industrial processing of cuttlefish (Illex argentinus). The effluents were produced in the processes of thawing (E1), softening (E2), boiling (E3) and gelation (E4). Our results showed that membranes with cut-off at 100, 30 and 10 kDa were an effective resource to protein concentration of E2 and E3 but limited for E1 and E4. In addition, E2 and E3 retentates led to remarkable antihypertensive and antioxidant activities, further improved by enzymatic hydrolysis. Also sequential ultrafiltration revealed the enrichment of these protein concentrates in peptides with high angiotensin-converting enzyme (ACE)-inhibitory activity. Thereby, UF-fractionation followed by proteolysis of protein concentrates from cuttlefish wastewaters offers new opportunities for the development of bioactive hydrolysates with application in the food industry. In addition, this approach contributes to an improved depuration of industrial wastewaters, reducing the treatment costs and leading to a decrease in its contaminating effect.     

Domestic wastewater as substrate for cellulase production by Trichoderma harzianum

Cellulase production using residues as substrate has been well described, as it is an interesting method of reducing the costs of processes, one of the main bottlenecks for the production of enzymes. This research describes for the first time the use of raw domestic wastewater, which is largely and continuously generated, as a culture base medium for cellulase production. The strain Trichoderma harzianum HBA03 was selected according to the highest activity produced for FPase (5.4 U/mL) and CMCase (8.2 U/mL). Peptone was selected as a nitrogen source and microcrystalline cellulose as the inducer for cellulase production, resulting in FPase activities of 5.6 and 5.0 U/mL and CMCase activities of 12.0 and 14.4 U/mL. The use of domestic wastewater as the culture medium led to an increase of 1.41 and 1.14 fold of FPase and CMCase production, respectively, compared to the synthetic medium. Production was also carried out in a bubble column reactor in which the maximum productivities achieved 10.2 U/L.h (FPase) and 64.6 U/L.h (CMCase). The presented results demonstrate the feasibility of the use of domestic wastewater for cellulases production, thereby contributing to the development of a sustainable process for reusing wastewater with a significant reduction in environmental impact.     

Biodegradation of lignocellulosic waste by Aspergillus terreus

Biodegradation of lignocellulosic waste by Aspergillus terreus is reported for the first time. This isolate produced 250 CMCase (carboxymethyl cellulase or endoglucanase) U.ml^-1 and biodegraded hay and straw during 3 days and the biomass production on straw was 5g.L^-1dry weight from 0.25 cm² inoculated mycellium. This strain secreted endocellulases and exocellulases in the culture medium, but some of the enzymes produced, remained cell membrane bound. Cell bound enzymes were released by various treatments. The highest amount of endoglucanase and exoglucanase was released when the cells were treated with sonication. Aspergillus terreus was added to two tanks containing sugar wastewater and pulp manufacturing waste, as a seed for COD removal. This fungus reduced the COD by 40–80 percent, also, ammonia was reduced from 14.5 mM to 5.6 mM in sugar beet wastewater. The effects of crude enzyme of this fungus for COD removal was studied.     

NUTRIENT SEQUESTRATION,BIOMASS PRODUCTION BY MICROALGAE AND PHYTOREMEDIATION OF SEWAGE WATER

The present work was aimed at analysing the role of inoculated microalgae in nutrient dynamics, bioremediation and biomass production of sewage water. Preliminary microscopic analyses of sewage water revealed the presence of different algal groups, with predominance of Cyanophyta. Among the inoculated strains, Calothrix showed highest dry cell weight (916.67 mg L^?1), chlorophyll and carotenoid content in tap water + sewage water (1:1) treatment. Significant removal of NO₃-N ranging from 57–78% and PO₄-P (44–91%) was recorded in microalgae inoculated tap water + sewage water. The total dissolved solids and electrical conductivity of tap water + sewage water after incubation with Calothrix sp. decreased by 28.5 and 28.0%, accompanied by an increase in dissolved oxygen from 4.4 to 6.4 mg L^?1 on the 20th day. Our investigation revealed the robustness of Calothrix sp. in sequestering nutrients (N and P), improving water quality and proliferating in sewage water.     

Kinetics of anaerobic degradation of glycol-based Type I aircraft deicing fluids

The kinetics of anaerobic degradation of glycol-based Type I aircraft deicing fluids (ADFs) were characterized using suspended-growth fill-and-draw reactors. Both Type I ADFs tested showed near-complete anaerobic degradability. First-order degradation rate constants of 3.5 d^-1 for the propylene glycol-based Type I ADF and 5.2 d^-1 for the ethylene glycol-based Type I ADF were obtained through continuous-culture means under mesophilic conditions (35 °C). Fill-and-draw operation at lower temperatures affected anaerobic degradability only minimally down to 25 °C but substantially below 25 °C. High Type I ADF feed concentrations substantially affected degradability. Batch testing of fill-and-draw reactors resulted in first-order degradation rate constants of 1.9 d^-1 for propylene glycol-based Type I ADF and 3.5 d^-1 for ethylene glycol-based Type I ADF.     

In-vitro compatibility evaluation of fungal mixed culture for bioconversion of domestic wastewater sludge

Six different fungal strains/isolates were selected after conducting a series of experiments of isolation and screening to evaluate their successful adaptation and growth to domestic wastewater sludge and its efficient bioconversion into compost. Two different fungi were grown in the same petri dish 4 cm apart in two culture media, potato dextrose agar (PDA) and malt extract agar (MEA). Fifteen different in-vitro interactions were studied and summarized according to five possible outcomes, i.e., mutual intermingling, partial mutual intermingling, inhibition at contact point, inhibition at a distance and replacement. The interaction of Trichoderma hazianum ^s Rifai with Phanerochaete chrysosporium 2094 was identified as mutual intermingling. The partial mutual intermingling of T. hazianum ^s with Mucor hiemalis Wehmer suggested compatibility of the two strains without showing any abnormal effects. Perhaps these two combinations may interact mutually in any mixed culture programme. The fungal strain Aspergillus versicolor Vuill performed as a strong repellent and all interactions exhibited deadlock/inhibition at a certain distance. The isolate RW-Pl 512 from the gill of a basidiomycete from a rotten wood stub actively replaced the strain M. hiemalis in in-vitro culture.     

The Potentiality of Free Gram-negative Bacteria for Removing Oil and Grease from Contaminated Industrial Effluents

Summary Eight bacterial species were isolated from vegetable oil and grease-contaminated industrial wastewater, only four of which were found to have the ability to degrade oil and grease in the contaminated wastewater. These isolates were identified according to morphological and biochemical profiles as, Pseudomonas sp. (L1), P. diminuta (L2), P. pseudoalcaligenes (L3), and Escherichia sp. (L5). The degradative capabilities of the identified bacterial isolates for Tween 20 (Tw20) were investigated under different pH levels (6.5, 7, 7.5, and 8), different temperatures (30 and 37 °C) and different concentrations of Tw20 (1, 1.5, and 2%). Results revealed differences in their optimum conditions for maximum degradation of vegetable oil. Bacterial isolates were tested individually or in combinations using synthetic aqueous medium supplemented with 1% palm oil, incubated at 30 °C, and agitated at 150 rev/min for 13 days. All the tested bacteria were able to degrade the palm oil completely and utilized the free fatty acids (FFA) as a carbon source. The combination M1 (Pseudomonas sp. and P. diminuta) produced the highest degradative activity, followed by M3 (Pseudomonas sp., P. diminuta and P. pseudoalcaligenes). Also M1 produced the highest activity in reducing COD (93%) and BOD₅ (100%).     

Comparative assessment of growth and biodegradation potential of soil isolate in the presence of pesticides

In Pakistan, to increase agricultural production, higher amounts of fertilizers and pesticides are being used. The residues of the applied pesticides stay in the environment and therefore causing contamination of air, water and land. Moreover, agricultural industries are also contributing relatively high quantities of toxic pesticides into the environment. Since most of them have no treatment facilities. These pesticides may be toxic, mutagenic or carcinogenic. They may be bioaccumulated or biomagnified by the biota. Therefore its removal from environmental systems needs special attention. In this study, bacterial isolate, Pseudomonas, designated as IES-Ps-1, was used to assess its potential for pesticide removal from industrial wastewater using the biosimulator (activated sludge process). During experimental studies conducted in the flask as well as in biosimulator, it was observed that IES-Ps-1 grows normally at low concentrations of added insecticides when compared with the control test (without pesticide). However, at high concentrations the microbial count decreased but no death occurred and the culture remained in lag phase. In many cases, the growth of organisms in the presence of the particular substrate serves as an indication about its metabolic potential. However, to confirm these results, chemical oxygen demand (COD) and HPLC analysis were performed. Under aerobic culture conditions using mechanical aerators in biosimulator, almost complete removal of Cypermethrin at 20 mg/L dose occurred during 48 h. The study findings indicate that IES-Ps-1 strain, can be used for the treatment of the pesticide contaminated environment. Such study may be valuable to scientist and engineers, who are trying to develop methods for the treatment of toxic organic waste using the biological treatment process.     

Biodegradation of phenol by enzymes from Pseudomonas sp. immobilized onto ultrafiltration membranes

A method of immobilizing enzymes from Pseudomonas sp. that decompose phenol on polymeric ultrafiltration membranes is described. Transport-separation properties of neutral and enzymic membranes have been compared and the optimal ultrafiltration process parameters of a model phenol solution have been determined. The immobilized enzyme system was applied to the biodegradation of phenol in coke wastewaters.     

Evaluation of protein extraction methods to improve meta-proteomics analysis of treated wastewater biofilms

Metaproteomics can be used to study functionally active biofilm-based bacterial populations in reclaimed water distribution systems, which in turn result in bacterial regrowth that impacts the water quality. However, existing protein extraction methods have differences in their protein recovery and have not been evaluated for their efficacies in reclaimed water biofilm samples. In this study, we first evaluated six different protein extraction methods with diverse chemical and physical properties on a mixture of bacterial cell culture. Based on a weighting scores-based evaluation, the extraction protocols in order of decreasing performance are listed as B-PER > RIPA > PreOmics > SDS > AllPrep > Urea. The highest four optimal methods on cell culture were further tested against treated wastewater non-chlorinated and chlorinated effluent biofilms. In terms of protein yield, our findings showed that RIPA performed the best; however, the highest number of proteins were extracted from SDS and PreOmics. Furthermore, SDS and PreOmics worked best to rupture gram-positive and gram-negative bacterial cell walls. Considering the five evaluation factors, PreOmics obtained highest weighted score, indicating its potential effectiveness in extracting proteins from biofilms. This study provides the first insight into evaluating protein extraction methods to facilitate metaproteomics for complex reclaimed water matrices.