Evaluation of simplified ester-linked fatty acid analysis (ELFA) for phospholipid fatty acid (PLFA) analysis of bacterial population.

Phospholipid fatty acid (PLFA) analysis is used for characterizing microbial communities based on their lipid profiles. This method avoids biases from PCR or culture, allowing data collection in a natural state. However, PLFA is labor-intensive due to lipid fractionation. Simplified ester-linked fatty acid analysis (ELFA), which skips lipid fractionation, offers an alternative. It utilizes base-catalyzed methylation to derivatize only lipids, not free fatty acids, and found glycolipid and neutral lipid fractions are scarcely present in most bacteria, allowing lipid fractionation to be skipped. ELFA method showed a high correlation to PLFA data (r = 0.99) and higher sensitivity than the PLFA method by 1.5-2.57-fold, mainly due to the higher recovery of lipids, which was 1.5-1.9 times higher than with PLFA. The theoretical limit of detection (LOD) and limit of quantification (LOQ) for the ELFA method indicated that 1.54-fold less sample was needed for analysis than with the PLFA method. Our analysis of three bacterial cultures and a simulated consortium revealed the effectiveness of the ELFA method by its simple procedure and enhanced sensitivity for detecting strain-specific markers, which were not detected in PLFA analysis. Overall, this method could be easily used for the population analysis of synthetic consortia.

Comparative evaluation of antimicrobial activity of spinel structured transition metal ferrites supported on reduced graphene oxide against pathogenic strains of bacteria and fungi.

One of the global challenges for living things is to provide pollution and harmful microbes-free environment. In this study, magnetically retrievable spinel-structured manganese zinc ferrite (Mn0.5Zn0.5Fe2O4) (MZF) was synthesized by a facile solvothermal method. Further, the MZF with different weight percentages (10 wt%, 50 wt%, and 80 wt%) were supported on reduced graphene oxide (rGO). The phase purity and morphology of MZF and MZF/rGO nanocomposite were confirmed by x-ray diffraction technique and scanning electron microscopy, respectively. The Fourier transform infrared spectroscopy, Raman, UV-visible spectroscopy, and thermogravimetric analyses of the as-synthesized nanocomposites were examined for the detection of various chemical groups, band gap, and thermal properties, respectively. The MZF/rGO nanocomposite exhibited significant antibacterial and antifungal activity againstEggerthella lenta, Enterococcus faecalis, Klebsiella pneumonia, Pseudomonas aeruginosa,andCandida albicanscompared to bare MZF and rGO. The high surface area of rGO plays a crucible role in antimicrobial analysis. Additionally, the antibacterial and antifungal activity is compared by synthesizing various metal ferrites such as MnFe2O4, ZnFe2O4, and Fe3O4. The 50 wt% MZF/rGO nanocomposite exhibits significantly high antibacterial activity. However, 10 wt% MZF/rGO nanocomposite shows good antifungal activity than Fe3O4, MnFe2O4, ZnFe2O4, MnZnFe2O4, 50 wt%, and 80 wt% MZF/rGO nanocomposites. These findings suggest that the prepared ferrite nanocomposites hold promise for microbial inhibition.

Effects of sludge retention time on sludge reduction by ultrasound treatment: Sludge characteristics, microbial community, and metabolism.

Both ultrasound and sludge retention time (SRT) enable the in-situ sludge reduction during wastewater treatment, but the influence of SRT on ultrasonic lysis - cryptic growth is unclear. This paper researched the influence of different SRTs on sludge lysis - cryptic growth using a sequential bio-reactor (SBR), then explained in details the changes of microorganisms in the SBR. The best SRT for sludge reduction was 30 d, and 47.29% reduction in sludge was achieved. The different SRTs changed the organic matter removal in the wastewater, and the removal rate decreased when SRT exceeded 60 d. The size of the sludge particles varied depending on the SRT, with the smallest size at SRT of 10d being 45.6 µm and the largest size at SRT of 90d being 110.0 µm. SEM showed that the sludge surface changed rough at longer SRT. FTIR and XPS showed notable effect in sludge functional group strength at SRT of 30 d. Extracellular polymeric substance (EPS) reduced the most at SRT of 30 d. The microbial communities of sludge varied with the SRT, and the unique main genus at SRT of 5, 15, 30 and 90 d were C10-SB1A, Lactococcus, Propioniciclava, Lactococcus, respectively. Furthermore, the SRT changed relative abundance of enzymes concerned with metabolism of carbon, nitrogen, and phosphorus. Similarly, SRT changed the metabolic rate, and the metabolic rate of carbon, nitrogen and phosphorus was best at SRT of 30 d.

Clinical characteristics and management outcome of acute infectious endophthalmitis.

PURPOSE: This study aimed to investigate the demographics, clinical characteristics, and management outcomes of patients with acute infectious endophthalmitis (AIE). METHODS: This retrospective chart review was conducted on all patients admitted with the clinical diagnosis of infectious endophthalmitis from 2017 to 2022. Demographic data, patients' clinical characteristics, the type of acute infectious endophthalmitis (post-operative, post-traumatic, bleb-associated, and endogenous endophthalmitis), the type of surgical procedure in the post-operative cases, the microbiologic analysis results of vitreous samples, therapeutic measures, and visual outcomes of patients were recorded. RESULTS: In this study, 182 participants, including 122 male (67%) and 60 (33%) female, were involved. The mean age of patients was 54.56 ± 21 years, with a range of 1-88 years old. The most prevalent type of AIE was post-operative (59.9%), followed by endogenous (19.2%), post-traumatic (17%), and bleb-associated (3.8%). The most common type of intraocular surgery in the post-operative subgroups of AIE patients was phacoemulsification (57.8%). The median (interquartile range) of the primary and final BCVA of patients was 1.5 (1.35, 1.85) and 0.65 (0.35, 1.35), respectively. Vitreous haziness grade (OR, 2.89; 95% CI, 1.11-5.74; p = 0.009) and the primary VA (OR, 60.34; 95% CI, 2.87-126.8; p = 0.008) revealed statistical significance for final vision loss. CONCLUSION: AIE is a devastating condition with poor visual outcomes, which presents with acute inflammatory signs and symptoms regardless of its type. However, prompt and appropriate treatment leads to visual recovery to a functional level in many patients.

Anaerobic digestion characteristics and key microorganisms associated with low-temperature rapeseed cake and sheep manure fermentation.

In this study, gas production from mixed anaerobic fermentation of rapeseed cake and sheep manure at low temperature (15.2-17.8 °C) was investigated in Qinghai rural household biogas digesters to understand the temporal dynamics of key microbial populations involved in fermentations. Different raw material ratios resulted in significantly different effects on biogas yields and microbial community compositions over 40 days. When the dry weight ratio of sheep manure to rapeseed cake was 1:2, the highest level of cumulative gas production was observed (122.92 m3·t-1). Firmicutes, Proteobacteria, Bacteroidetes, and Actinobacteria were the dominant bacterial phyla among the 29 digester samples (total relative abundances > 79.23%), followed by Synergistetes (4.09-10.7%). Lactobacillus was the most abundant genus in the biogas digesters with high rapeseed cake contents (average relative abundances: 14.68%), while Peptoniphilus exhibited higher abundances (12.69%) in the mixed treatments. In addition, unclassified Synergistaceae abundances (6.64%) were positively associated with biogas production variation among treatments. Bacteroides (5.74%) and Pseudomonas (5.24%) both accounted for larger proportions of communities in the digesters that used more sheep manure. Methanomicrobiales (66.55%) was the most dominant archaeal group among digesters, with Methanogenium (41.82%) and Methanoculleus (16.55%) representing the main gas-producing archaeal genera; they were more abundant in biogas digesters with higher sheep manure contents and higher rapeseed cake contents, respectively. VFAs and pH were the main factors associated with differences in microbial communities among the 29 samples. Specifically, VFA concentrations were positively correlated with Lactobacillus, Methanoculleus and Methanothrix abundances, while pH was positively correlated with Bacteroides, Pseudomonas, and Methanobacterium abundances.

Effect of Toxic Phthalate-Based Plasticizer on the Biodegradability of Polyhydroxyalkanoate.

While new biodegradable materials are being rapidly introduced to address plastic pollution, their end-of-life impacts remain unclear. Biodegradable plastics typically comprise a biopolymer matrix with functional additives and/or solid fillers, which may be toxic. Here, using an established method for continuous biodegradation monitoring, we investigated the impact of a commonly used plasticizer, dibutyl phthalate (DBP), on the biodegradation of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) in soil. The presence of DBP delayed the initial stage of PHBV biodegradation but then accelerated subsequent rates of biodegradation. Furthermore, it led to significant increases in total bacterial and fungal biomass and altered the composition of microbial communities with significant increases in the relative abundances of Thauera (gammaproteobacterial) and Mucor circinelloides (fungal) populations. It is proposed, with evidence from biodegradation behavior and microbial analysis, that the presence of DBP likely stimulated a microbial community shift, introduced higher proportions of more readily degradable amorphous regions from the plasticizing effect, and facilitated access to the bulk polymer matrix for microorganisms or at least their associated enzymes. These effects in combination overcame the initial inhibition effect of the DBP and resulted in a net increase in the rate of biodegradation of PHBV.

The toxicity of the monoterpenes from lemongrass is mitigated by the detoxifying symbiosis of bacteria and fungi in the tick Haemaphysalis longicornis.

The entry mode of terpenes into the atmosphere is via volatilization of hydrocarbons from foliage over heavily forested areas besides entering the environment through surface water runoff. Some monoterpenes in essential oils are phytotoxins, acting as plant chemical defenses against bacteria or fungi infections and plant-eating insects. For organisms to survive, their enzymatic systems are activated in response to an assault by potentially harmful compounds. Certain bacterial and fungal genera have developed special abilities to transform toxic terpenes into less toxic derivatives. Here, we investigated the response of the bacterial and fungal community in Haemaphysalis longicornis exposed to Cymbopogon citratus (lemongrass) essential oil (EO) and citronellal. Sequencing of bacterial 16S rRNA and fungal ITS1 regions on an Illumina NovaSeq PE250 sequencing platform was performed for H. longicornis tick samples treated with 15 and 20 mg/mL of lemongrass essential oil and citronellal. The diversity recorded in samples treated with C. citratus EO was higher in comparison to those treated with citronellal but significantly lower in the control samples as reflected by the Shannon diversity index. All major H. longicornis bacterial phyla, including Proteobacteria (93.81 %), Firmicutes (2.58 %), and Bacteroidota (0.99 %) were detected. A switch of dominance from Coxiella to Pseudomonas, which has high biotransformation capacity, was observed in the bacterial community, whereas the phylum Ascomycota (Genera: Aspergillus, Archaeorhizomyces, Alternaria, and Candida) dominated in the fungal community indicating detoxifying symbiosis. Other significantly abundant bacterial genera include Ralstonia, Acinetobacter, Vibrio, and Pseudoalteromonas, while Ganoderma and Trichosporon (yeasts) spp. represented the fungi Basidiomycota. This study expanded the understanding of enzymatic modification of phytotoxic substances by microorganisms, which could provide deeper insights into the mitigation of harmful phytotoxins and the synthesis of eco-friendly derivatives for the control of ticks.

Development of a Smartphone-Integrated Reflective Scatterometer for Bacterial Identification.

We present a smartphone-based bacterial colony phenotyping instrument using a reflective elastic light scattering (ELS) pattern and the resolving power of the new instrument. The reflectance-type device can acquire ELS patterns of colonies on highly opaque media as well as optically dense colonies. The novel instrument was built using a smartphone interface and a 532 nm diode laser, and these essential optical components made it a cost-effective and portable device. When a coherent and collimated light source illuminated a bacterial colony, a reflective ELS pattern was created on the screen and captured by the smartphone camera. The collected patterns whose shapes were determined by the colony morphology were then processed and analyzed to extract distinctive features for bacterial identification. For validation purposes, the reflective ELS patterns of five bacteria grown on opaque growth media were measured with the proposed instrument and utilized for the classification. Cross-validation was performed to evaluate the classification, and the result showed an accuracy above 94% for differentiating colonies of E. coli, K. pneumoniae, L. innocua, S. enteritidis, and S. aureus.

Plastic-containing food waste conversion to biomethane, syngas, and biochar via anaerobic digestion and gasification: Focusing on reactor performance, microbial community analysis, and energy balance assessment.

To manage the mixture of food waste and plastic waste, a hybrid biological and thermal system was investigated for converting plastic-containing food waste (PCFW) into renewable energy, focusing on performance evaluation, microbial community analysis, and energy balance assessment. The results showed that anaerobic digestion (AD) of food waste, polyethylene (PE)-containing food waste, polystyrene (PS)-containing food waste, and polypropylene (PP)-containing food waste generated a methane yield of 520.8, 395.6, 504.2, and 479.8 mL CH4/gVS, respectively. CO2 gasification of all the plastic-containing digestate produced more syngas than pure digestate gasification. Syngas from PS-digestate reached the maximum yield of 20.78 mol/kg. During the digestate-derived-biochar-amended AD of PCFW, the methane yields in the biochars-amended digesters were 6-30% higher than those of the control digesters. Bioinformatic analysis of microbial communities confirmed the significant difference between control and biochar-amended digesters in terms of bacterial and methanogenic compositions. The enhanced methane yields in biochars-amended digesters could be partially ascribed to the selective enrichment of genus Methanosarcina, leading to an improved equilibrium between hydrogenotrophic and acetoclastic methanogenesis pathways. Moreover, energy balance assessment demonstrated that the hybrid biological and thermal conversion system can be a promising technical option for the treatment of PCFW and recovery of renewable biofuels (i.e., biogas and syngas) and bioresource (i.e., biochar) on an industrial scale.

A study on the shelf life of cookies incorporated with sapota and beetroot leaf powders.

The addition of edible fiber could affect the shelf life of cookies, which can have a positive or negative impact depending on the source of fiber. This study is in continuation of two previously published papers to investigate the storage stability of cookies incorporated with 4.5% beetroot leaf powder (BLP), with 7% sapota fiber powder (SFP) and reference cookies during 15 months at ambient temperature by analyses of physicochemical, microbial and sensory properties on each specified month using international standard methods. It was found that with increasing storage period, there was an increment in moisture content, peroxide value, free fatty acids and microbial population including total aerobic bacteria and yeast and mold colonies of all cookies; the lowest values being for cookies with 7% SFP (5.70%, 4.12 mEqO2/1000 g cookie's fat, 1.47%, 2.73 and 2.36 log CFU/g dried cookie, respectively). In contrast, the reverse trend was found in pH value. At the end of storage, a significant difference (p ≤ 0.05) was observed between reference cookies and other cookies regarding moisture content, peroxide value, free fatty acids and overall sensory acceptability; the quality of cookies supplemented with 7% SFP being desirable, followed by cookies with 4.5% BLP, and then reference cookies.

Effects of zinc oxide nano particle on fortified tilapia mince during refrigerated storage (4 ± 1 °C).

Microbial and zinc concentration changes in Tilapia (Oreochromis niloticus) mince, fortified with zinc oxide nano particle during storage for 18 days at 4 ± 1 °C were investigated. During the present study the samples treated with ZnO nano particles T4 (60 ppm) and T5 (80 ppm) were recorded to have the lowest (p < 0.05) Total Plate Count (TPC) figures among all the treatments suggesting a significant antimicrobial effect of ZnO nano partials. The control sample without fortification did not meet the daily requirement of Zn for an adult. The T1 (inorganic ZnO @ 20 ppm) samples meet the dietary requirements till 3 days of storage where, sample T3, T4, T5 and T6 (ZnO nano particles @ 40 ppm, 60 ppm, 80 ppm and 100 ppm respectively) provides enough Zn till 6 days under storage at 4 ± 1 °C and in certain cases it is more than the dietary requirement of 10-15 mg/day for an adult individual. In the present study Zn concentration was significantly (p < 0.05) decreased in control. Hence, the intake of tilapia mince of these treatments may be adjusted accordingly to provide dietary Zn. Fortification of tilapia mince with Zn will not only improve the shelf life of the mince but also prove to be a good food fortification strategy to eradicate Zn deficiency.

A protocol for umbilical cord tissue cryopreservation as a source of mesenchymal stem cells.

Mesenchymal stem cells (MSC) differentiate into different cell types and have immunomodulatory and paracrine effects. Cryopreservation of umbilical cord tissue as a source of MSC is very promising for regenerative medicine. We aim to evaluate a protocol for cryopreserving this tissue sectioned into small fragments with viable MSC. A total of 723 samples were frozen, thawed and cultured to obtain primary cultures of MSC. These were followed until 90-100% confluence and flow cytometric analysis were performed to confirm the mesenchymal phenotype. Samples in which protocol alterations at the collection of the samples were reported, were excluded for microbial contamination analysis leaving a total of 634 samples composed of 181 vaginal and 453 cesarean births. All cultures reach confluence with a media of 22.57 days and 97% in 28 or fewer days. Evaluated cultures showed low percentage of CD45+ and high of CD73 and CD90. Eight samples were subcultured 4 or 5 times and differentiated to chondrocytes and osteocytes to test differentiation potential with positive results. Umbilical cord tissue collections showed similar microbial profile and risk factors to those reported of umbilical cord blood collections, but with higher contamination frequencies. Cryopreserved tissue samples had viable cells that can be expanded without losing differentiation potential. Higher contamination frequencies compared to umbilical cord blood collection are not surprising, however, microbial load and survival of microorganisms to cryopreservation are expected to be lower.

Assessment of microbial and heavy metal contamination in shallow hand-dug wells bordering Ona River, Southwest Nigeria.

Ona River is one of the three major rivers draining the city of Ibadan. Groundwater is the major source of drinking water in the metropolis; however, data on quality of shallow aquifers bordering Ona River is relatively scarce. This study aimed to evaluate bacteriological status, heavy metal content, and associated human and ecological health risks in hand-dug wells nearby Ona River. A total of 24 water samples from 12 sampling points were collected for chemical and microbial analyses. Heavy metals and microbial pathogens were analyzed using atomic absorption spectrometry and total plate count methods, respectively. Analyses of microbial and heavy metal (HMs) data showed that shallow hand-dug wells within the vicinity of Ona River were bacteriologically contaminated while most of analyzed heavy metals (except manganese) exceeded the drinking water quality standards. Interpretation of microbial and heavy metal (HMs) data identified predominance of anthropogenic activities as the major source of contamination in drinking water. Further scrutiny of HM data through integrated pollution indices identified two nearby wells (S7 and S8) exceed the safe limits and pose considerable risk to inhabitants. In terms of ecological risk index (ER), cadmium exhibited considerable to very high ER in all collected samples while manganese and zinc showed low ER in all analyzed water samples. Potential of non-carcinogenic risk through ingestion pathway in the study area was identified with the order of contributive ratios by HMs as Cd > Pb > Zn > Fe > Mn. The calculated target hazard quotient (THQ) due to ingested HMs for three human population categories exceeds the safe limit in the order of adult < children < infants. The study revealed the deteriorated state of waterside shallow hand-dug wells that need immediate actions by relevant stakeholders in water management. The study recommends improved hygienic practices, pretreatment of water before use, and most importantly, provision of potable pipe-borne water supply to the residents of the study area.

Effect of packaging materials and storage conditions on the microbial quality of pearl millet sourdough bread.

Sourdough is one of the oldest methods of cereal fermentation applied mainly for the sole purpose of baking and has been proven to enhance the production of microbiologically safe products. This study investigated the effect of packaging materials and storage conditions on the microbial quality and some intrinsic parameters of the sourdough bread. Pearl millet flour was naturally fermented for 72 h to obtain sourdough which was used with pearl millet flour to produce sourdough bread while the control bread was produced with pearl millet flour and yeast. The bread samples were packaged in low density polyethylene and aluminium foil and stored at -5, 4, 6, 28 and 37 °C. The total bacteria count (log cfu/g) and total fungal count (spore/g) increased with an increase in storage temperature and storage days. Fungi colonies isolated from stored bread samples include species of Rhizopus, Aspergillus, Penicillium and Mucor. A significant increase (p ≤ 0.05) in the pH and decrease in the moisture content of the bread samples were observed as storage period and storage temperature increased. Sourdough fermentation improved the microbial qualities and extended the shelf life of bread.

Microbiota composition of captive bluestreak cleaner wrasse Labroides dimidiatus (Valenciennes, 1839).

The Labroides dimidiatus is one of the most traded marine ornamental fishes worldwide, yet not much is known about the microflora associated with this fish. This study is designed to investigate the bacteria composition associated with captive L. dimidiatus and its surrounding aquarium water. The fish and carriage water were obtained from well-known ornamental fish suppliers in Terengganu Malaysia. Bacteria present on the skin and in the stomach and the aquarium water were enumerated using culture-independent approaches and next-generation sequencing (NGS) technology. A total of 3,238,564 valid reads and 828 total operational taxonomic units (OTUs) were obtained from the three metagenomic libraries using NGS analysis. Of all the 15 phyla identified in this study, Proteobacteria, Bacteroidetes, Firmicutes, and Actinobacteria were the most prevalent in all samples. Also, 170 families belonging to 36 bacteria classes were identified. Although many of the bacteria families were common in the skin, gut, and aquarium water (39%), about 26% of the families were exclusive to the aquarium water alone. Therefore, any substantial change in the structure and abundance of microbiota (especially pathogenic bacteria) reported in this study may serve as an early sign for disease infection in the species under captivity. KEY POINTS: • Proteobacteria was the most dominant. • The microbiota was either shared or exclusively in samples.

Enhanced hydrolysis of lignocellulose in corn cob by using food waste pretreatment to improve anaerobic digestion performance.

This study aims to enhance hydrolysis and anaerobic digestion of corn cob (CC) by using food waste (FW) pretreatment. FW, which tends to be acidification in fermentation, was applied in this process as an acid-like agent to accelerate lignocellulose hydrolysis, aiming to promote methane yield in further digestion process. The effect of FW pretreatment on pH, soluble chemical oxygen demand (SCOD), volatile fatty acids (VFAs), cellulose/hemicellulose contents and cellulose crystallinity are specially focused. FW:CC = 1:3 based on volatile solid (VS) was found to be the optimal mixing ratio in pretreatment and its hydrolysis efficiency was 28% higher than the control group. An increase of 13.2% in cellulose reduction and a decrease of 6.7% in cellulose crystallinity was achieved at this ratio. Supplementation of FW increased VFA concentrations in slurry mixture that directly change the activities of enzymes and microorganisms. In the stage of methane production, the digester A3 (FW:CC = 1:6 based on VS) with higher hydrolysis efficiency presented the best performance in methane production with a specific methane yield of 401.6 mL/g·VS, due to the recovery of the pH in this digester to the optimal pH range for methanogens' metabolism (pH 6.3-7.2). Kinetics studies of cellulose/hemicellulose degradation indicated that the pretreatment of FW could improve the degradation of cellulose. Three-dimensional excitation emission matrix (3DEEM) results further confirmed that FW play an important role in lignocellulose hydrolysis. In addition, variations of lignocellulosic textures during the pretreatment were also cleared by using field emission-scanning electron microscopy (FE-SEM) analysis.

Enhanced bioremediation of diesel range hydrocarbons in soil using biochar made from organic wastes.

Hydrocarbon contamination due to anthropogenic activities is a major environmental concern worldwide. The present study focuses on biochar prepared from fruit and vegetable waste and sewage sludge using a thermochemical approach and its application for the enhanced bioremediation (biostimulation and bioaugmentation) of diesel-polluted soil. The biochar was characterized using FTIR (Fourier-transform infrared spectroscopy), elemental analysis, surface area analysis, and pore analysis. Adsorption experiments showed that hydrocarbon degradation was attributed to biological processes rather than adsorption. The study found that various biochar amendments could significantly increase the rate of hydrocarbon biodegradation with removal efficiencies > 70%. Bioaugmentation using cow dung further improved the removal efficiency to 82%. Treatments showing the highest degree of removal efficiency indicated the presence of 27 different bacteria phyla with Proteobacteria and Actinobacteria as the most abundant phyla. The present study concludes that biochar amendments have great potential for enhancing the bioremediation of soils contaminated with diesel range hydrocarbons.

Physico-chemical and microbial characterization of compartment-wise profiles in an anammox baffled reactor.

In this study, compartment-wise investigation of an anammox baffled reactor (AnBR) was performed. The AnBR achieved steady-state conditions after a start-up period of ∼50 days and achieved NH4 and NO2 conversion percentages of 88.5 and 99.3%, respectively. Examination of the nitrogen mass balance revealed that an AnBR with a two-compartment configuration was sufficient for nitrogen loading rates (NLRs) ranging from 0.125 to 1.975 kg N/m3/d and resulted in a nitrogen removal efficiency (NRE) of 86.7-93.7%. Higher NLRs (4.04-5.05 kg N/m3/d) required four compartments to achieve an NRE of 82.2-87.1%. Further, an overall NLR increase of up to 5.93 ±â€¯0.23 kg N/m3/d resulted in complete AnBR failure. The maximum nitrogen removal rate was consistently recorded in the 1st compartment for all NLRs examined; as a result, this compartment exhibited the highest bacterial activity. Biomass concentration, specific anammox activity, extracellular polymeric substances, and average granule diameter in the 1st compartment with an overall NLR of 0.05 kg N/m3/d were estimated to be 11.2 gVSS/L, 0.03 mg N/gVSS/h, 84.3 mg/gVSS, and 0.65 mm, respectively. These values increased to 26.1 gVSS/L, 11.80 mg N/gVSS/h, 242.1 mg/gVSS, and 2.31 mm, respectively, when the overall NLR was incremented to 4.04 kg N/m3/d. However, a gradual reduction in bacterial activity was observed from the 1st to the 5th compartment. The microbial community analysis indicated that the dominant phyla in the 1st compartment (NLR of 0.252 kg N/m3/d) with the highest nitrogen removal were Chloroflexi (38.13%), Planctomycetes (22.62%), and Proteobacteria (14.75%).

Influence of inoculum variation on formation and stability of aerobic granules in oily wastewater treatment.

This study provides extensive information about oily wastewater treatment in aerobic granular reactors (AGR) using three different inoculums from sewage, refinery and brewery. Initially, sodium acetate was used for granule formation while AGR with brewery inoculum had maximum granule size (5.44 ±â€¯0.05 mm) and extracellular polymeric substances (EPS: 471.22 ±â€¯2.0 mg/g VSS). But, during emulsified diesel exposure, refinery sludge granules achieved maximum granule size of 3.49 ±â€¯0.01 mm and EPS of 204.85 ±â€¯2.01 mg/g VSS with maximum 67.39 ±â€¯0.15% oil removal efficiency. AGRs achieved 99.9 ±â€¯0.05% chemical oxygen demand (COD) and 91.67 ±â€¯0.14% ammonia nitrogen (NH4+-N) removal efficiencies. Refinery granules remained stable at maximum 310 ±â€¯10 mg/L diesel concentration whereas, the stability thresholds for sewage and brewery granules were 170 ±â€¯15 and 250 ±â€¯10 mg/L, respectively. Brevibacterium paucivorans strain SG001, Micrococcus aloeverae strain SG002 and Staphylococcus hominis strain SG003 were identified as the major pollutant degraders isolated from sewage, refinery and brewery sludge. Micrococcus aloeverae strain SG002 exhibited maximum pollutant removal efficiencies (COD: 99.9 ±â€¯0.01%, NH4+-N: 99.9 ±â€¯0.01%, oil: 61.34 ±â€¯0.85%) among the three species. Re-addition of sodium acetate restored granule structure and stability.

Freshness Assessment and Shelf-Life Prediction for Seriola dumerili from Aquaculture Based on the Quality Index Method.

Fish and fish-based products are easily perishable foods due to different factors, including fragile organization, abundant endo-enzymes, psychrophilic bacteria, and impact of pre-harvest operations, that contribute to reducing its value. Therefore, a timely effective method for fish freshness and shelf-life evaluation is important. In this context, this study aimed to develop a sensory scheme based on the Quality Index Method (QIM) (sensory table and point system) for freshness monitorization and shelf-life prediction for Seriola dumerili from aquaculture in Madeira Island. Evaluation of appearance, texture, eyes, and gills was performed during 20 days of storage on ice (0 ± 1 °C). The shelf-life prediction was supported by the analysis of microorganisms (total viable colonies, TVC, counts), texture (Torrymeter), and production of trimethylamine (TMA), evaluated by HS-SPME-GC-MS and validated according to Association of Official Analytical Chemists AOAC guidelines. The result is a QIM scheme with 25 demerit points, where zero indicates total freshness. From the integration of sensory analysis, microbial growth at the time of rejection (TVC, 108 cfu/cm2 and H2S producers, 107 cfu/cm2), texture (Torrymeter value < 8), and TMA analyses (>12.5 mg/100 g), shelf-life was estimated as 12 days (±0.5 days). The obtained results show the high-throughput potential of the developed method for fish freshness assessment and shelf-life prediction. This QIM scheme is a secure way to measure quality and provide users with a reliable standardized fish freshness measure.