Microorganism-mediated biodegradation for effective management and/or removal of micro-plastics from the environment: a comprehensive review

Micro- plastics (MPs) pose significant global threats, requiring an environment-friendly mode of decomposition. Microbial-mediated biodegradation and biodeterioration of micro-plastics (MPs) have been widely known for their cost-effectiveness, and environment-friendly techniques for removing MPs. MPs resistance to various biocidal microbes has also been reported by various studies. The biocidal resistance degree of biodegradability and/or microbiological susceptibility of MPs can be determined by defacement, structural deformation, erosion, degree of plasticizer degradation, metabolization, and/or solubilization of MPs. The degradation of microplastics involves microbial organisms like bacteria, mold, yeast, algae, and associated enzymes. Analytical and microbiological techniques monitor microplastic biodegradation, but no microbial organism can eliminate microplastics. MPs can pose environmental risks to aquatic and human life. Micro-plastic biodegradation involves fragmentation, assimilation, and mineralization, influenced by abiotic and biotic factors. Environmental factors and pre-treatment agents can naturally degrade large polymers or induce bio-fragmentation, which may impact their efficiency. A clear understanding of MPs pollution and the microbial degradation process is crucial for mitigating its effects. The study aimed to identify deteriogenic microorganism species that contribute to the biodegradation of micro-plastics (MPs). This knowledge is crucial for designing novel biodeterioration and biodegradation formulations, both lab-scale and industrial, that exhibit MPs-cidal actions, potentially predicting MPs-free aquatic and atmospheric environments. The study emphasizes the urgent need for global cooperation, research advancements, and public involvement to reduce micro-plastic contamination through policy proposals and improved waste management practices.

Microbial production of docosahexaenoic acid (DHA): biosynthetic pathways, physical parameter optimization, and health benefits

Omega-3 fatty acids, including docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), and α-linolenic acid (ALA), are essential polyunsaturated fatty acids with diverse health benefits. The limited conversion of dietary DHA necessitates its consumption as food supplements. Omega-3 fatty acids possess anti-arrhythmic and anti-inflammatory capabilities, contributing to cardiovascular health. Additionally, DHA consumption is linked to improved vision, brain, and memory development. Furthermore, omega-3 fatty acids offer protection against various health conditions, such as celiac disease, Alzheimer's, hypertension, thrombosis, heart diseases, depression, diabetes, and certain cancers. Fish oil from pelagic cold-water fish remains the primary source of omega-3 fatty acids, but the global population burden creates a demand-supply gap. Thus, researchers have explored alternative sources, including microbial systems, for omega-3 production. Microbial sources, particularly oleaginous actinomycetes, microalgae like Nannochloropsis and among microbial systems, Thraustochytrids stand out as they can store up to 50% of their dry weight in lipids. The microbial production of omega-3 fatty acids is a potential solution to meet the global demand, as these microorganisms can utilize various carbon sources, including organic waste. The biosynthesis of omega-3 fatty acids involves both aerobic and anaerobic pathways, with bacterial polyketide and PKS-like PUFA synthase as essential enzymatic complexes. Optimization of physicochemical parameters, such as carbon and nitrogen sources, pH, temperature, and salinity, plays a crucial role in maximizing DHA production in microbial systems. Overall, microbial sources hold significant promise in meeting the global demand for omega-3 fatty acids, offering an efficient and sustainable solution for enhancing human health.

Evaluation of Bacillus clausii CSI08, Bacillus megaterium MIT411 and a Bacillus cocktail on gastrointestinal health: a randomised, double-blind, placebo-controlled pilot study

In the present study, the safety, tolerance and impact of 1×10⁹ cfu Bacillus clausii CSI08, 1×10⁹ cfu Bacillus megaterium MIT411 and a probiotic cocktail containing Bacillus subtilis DE111^®, Bacillus megaterium MIT411, Bacillus coagulans CGI314, and Bacillus clausii CSI08 with a total count of 2.0×10⁹ cfu administered daily were assessed as compared with a maltodextrin containing placebo control. A total of 98 study participants received daily doses for 45 days, followed by a washout period of 2 weeks. A questionnaire to capture the incidence and duration of upper respiratory tract, urinary tract and/or gastrointestinal complaints and a diary to capture stool regularity and consistency was kept daily to record compliance throughout the 45 days. Faecal and blood samples were collected for microbiological and haematological analysis at the start and end of the treatment period. The probiotic cocktail significantly decreased the incidence of loose stools throughout the entire study. The recorded respiratory, urinary and gastrointestinal symptoms, defecation frequency and other stool consistency were not influenced. No clinically relevant changes in blood parameters, such as liver and kidney function and no serious adverse events appeared during and after administration. There were no changes in symptoms including sadness, irritability, energy, appetite, tension, stress, sleep, cardiovascular events, aches and pains, and dizziness as determined by a mood questionnaire administered to participants at baseline and at the end of the treatment period. Similarly, the measured inflammatory cytokines, antioxidant levels, cholesterol, triglycerides, free amino acids or minerals remained unaffected. There were no negative changes in alpha or beta diversity of the microbiota with any of the treatment groups. These promising data suggest that these treatments were safe and well tolerated, and further work with larger cohorts are justified to determine the efficacy of these potential probiotics in select demographic groups. Trial registration number with clinicaltrials.gov at NCT04758845.

Acute physiological effects following Bacillus subtilis DE111 oral ingestion - a randomised, double blinded, placebo-controlled study

Previous studies using ileostomy samples from study participants demonstrated that the spore-forming probiotic Bacillus subtilis DE111® can germinate in the small intestine as early as 4 hours after ingestion. Metabolomics, proteomics and sequencing technologies, enabled further analysis of these samples for the presence of hypoglycaemic, hypolipidemic, antioxidant, anti-inflammatory and antihypertensive molecules. In the DE111 treatment group, the polyphenols trigonelline and 2,5-dihydroxybenzoic acid, orotic acid, the non-essential amino acid cystine and the lipokine 12,13-diHome were increased. DE111 also reduced acetylcholine levels in the ileostomy samples, and increased the expression of leucocyte recruiting proteins, antimicrobial peptides and intestinal alkaline phosphatases of the brush border in the small intestine. The combination of B. subtilis DE111 and the diet administered during the study increased the expression of the proteins phosphodiesterase ENPP7, ceramidase ASAH2 and the adipokine Zn-alpha-2-glycoprotein that are involved in fatty acid and lipid metabolism. Acute B. subtilis DE111 ingestion had limited detectable effect on the microbiome, with the main change being its increased presence. These findings support previous data suggesting a beneficial role of DE111 in digestion, metabolism, and immune health that appears to begin within hours of consumption.

Biobutanol production from sustainable biomass process of anaerobic ABE fermentation for industrial applications

The growing population increases the need to develop advanced biological methods for utilizing renewable and sustainable resources to produce environmentally friendly biofuels. Currently, energy resources are limited for global demand and are constantly depleting and creating environmental problems. Some higher chain alcohols, like butanol and ethanol, processing similar properties to gasoline, can be alternate sources of biofuel. However, the industrial production of these alcohols remains challenging because they cannot be efficiently produced by microbes naturally. Therefore, butanol is the most interesting biofuel candidate with a higher octane number produced naturally by microbes through Acetone-Butanol-Ethanol fermentation. Feedstock selection as the substrate is the most crucial step in biobutanol production. Lignocellulosic biomass has been widely used to produce cellulosic biobutanol using agricultural wastes and residue. Specific necessary pretreatments, fermentation strategies, bioreactor designing and kinetics, and modeling can also enhance the efficient production of biobutanol. The recent genetic engineering approaches of gene knock in, knock out, and overexpression to manipulate pathways can increase the production of biobutanol in a user friendly host organism. So far various genetic manipulation techniques like antisense RNA, TargeTron Technology and CRISPR have been used to target Clostridium acetobutylicum for biobutanol production. This review summarizes the recent research and development for the efficient production of biobutanol in various aspects.

Comparison and risk stratification of patients presenting with syncope in emergency department

Funding Acknowledgements

Type of funding sources: None.

Introduction :

Syncope is the sudden loss of consciousness, associated with an inability to maintain postural tone, with immediate and spontaneous recovery without requiring electrical or chemical cardioversion. It is a common condition associated with frequent hospitalization or visits to the emergency department. It has a prevalence of 40%, considering a lifetime of 70 years and an annual incidence of 6%. The prognosis after syncope ranges from relatively benign for vasovagal to poor for ventricular tachyarrhythmia, but invariably creates anxiety and potentially life-changing disruption demanding timely resolution Overall, morbidity and mortality in syncope patients are low, but 1-year mortality can reach significantly higher in certain subgroups.

Purpose :

To compare the mortality rates in men and women so that management of the disease and comorbidities can be done accordingly.

Methods :

Anyone who presented to the ED with transient loss of consciousness (TLOC) between 2015 and 2018 (n = 11,718) underwent evaluation for syncope. Initial evaluation included history, physical exam, orthostatic blood pressure, heart rate measurement and a 12-lead ECG with or without echocardiogram. All patients were followed up from their initial ED visit until either April 30, 2019, or death, whichever occurred first.

Results :

Among the patients who presented to the ED, 1,011 (8.62%) females and 1,391 (11.87%) males were admitted to inpatient facilities. The median age of females at the time of diagnosis was 49 years as compared to 54 years for males. Moreover, females had fewer comorbidities (67.9% with Charlson/Deyo comorbidity score of 0) as compared to males (61.8% with Charlson/Deyo comorbidity score of 0). At 30 days, among those admitted, females had a mortality rate of 2.2% vs. 5.1% for males, and among those discharged, females had a mortality rate of 0.1% vs. 0.6% for males (P < .001 for both). At 1 year, among those admitted, females had a mortality rate of 10.9% vs. 15.6% for males, and among those discharged, females had a mortality rate of 1.8% vs. 3.2% for males (P < .001 for both). All data were analyzed on SPSS version 20 and it was found that males had a 1.2 fold greater risk for death at 1 year compared to females.

Conclusion : By comparing the mortality rates of males and females presenting in the emergency department with syncope, we concluded that the mortality rate is higher in males. This finding will help us to manage the high-risk patients of syncope accordingly.

Survey on recent developments in automatic detection of diabetic retinopathy

Diabetic retinopathy (DR) is a disease facilitated by the rapid spread of diabetes worldwide. DR can blind diabetic individuals. Early detection of DR is essential to restoring vision and providing timely treatment. DR can be detected manually by an ophthalmologist, examining the retinal and fundus images to analyze the macula, morphological changes in blood vessels, hemorrhage, exudates, and/or microaneurysms. This is a time consuming, costly, and challenging task. An automated system can easily perform this function by using artificial intelligence, especially in screening for early DR. Recently, much state-of-the-art research relevant to the identification of DR has been reported. This article describes the current methods of detecting non-proliferative diabetic retinopathy, exudates, hemorrhage, and microaneurysms. In addition, the authors point out future directions in overcoming current challenges in the field of DR research.

Staphylococcus aureus carrying lukS/F Panton-Valentine Leukocidin (PVL) toxin genes in hospitals of Lahore city

INTRODUCTION

Panton Valentine-Leukocidin (PVL) toxin is secreted by Staphylococcus aureus and is mostly associated with skin and soft tissue infections (SSTI). This study aims to find out the prevalence of lukS/F-PV gene, which encode PVL toxin from strains of SSTI, burn wounds and nasal colonizers of out-patients and to measure the antimicrobial susceptibility of S. aureus isolates.

METHODOLOGY

This is an analytical observational cross-section study and was conducted from July 2014 to June 2015 at four tertiary care hospitals and PCSIR Laboratories Complex, Lahore, Pakistan. A total of 376 random clinical swabs were collected from SSTI (n = 179), nasal nares (n = 134) and burn wounds (n = 63) from out-patients' departments (OPD). The specimens were cultured on nutrient and mannitol salt agar (MSA) and the organism was identified by catalase, coagulase, and DNase tests. Antimicrobial susceptibility, methicillin, inducible clindamycin, and high-level mupirocin (HLMR) resistance were determined as per CLSI guidelines. Molecular identification of mecA and lukS/F-PV genes was performed by PCR.

RESULTS

We isolated 127 S. aureus, where 41 (32.3%) were MRSA and 86 (67.7%) were MSSA. All MRSA carried mecA gene whereas lukS/F-PV gene was found in 21 MRSA and 31 MSSA strains. Overall, a high antimicrobial resistance was found against MRSA and lukS/F-PV positive MSSA. Inducible clindamycin and high-level mupirocin resistance (HLMR) was 23.6% and 19.5% respectively.

CONCLUSIONS

A high rate of PVL toxin gene was detected among S. aureus strains and a high prevalence of antimicrobial resistant strains was observed.

Homotypic and heterotypic immune responses to group A rotaviruses in parenterally immunized sheep

Immune responses to human rotaviruses were investigated in sheep with a view to obtaining antibodies for passive immunotherapy of humans. Eighteen adult sheep with previous natural exposure to rotavirus serotypes G3 and G6 were immunized parenterally with purified preparations of either individual rotavirus serotypes G1, G2, G3, G4 and G8, or a mixture thereof. Two additional sheep were kept as control animals with the flock. The antibody responses were measured on serial serum samples by neutralization tests. The homotypic antibody response ranged from 100-fold (rarely) up to 100,000-fold increases in titre. Heterotypic responses against serotypes G3 and G6 were demonstrated in 7/12 and 15/18 sheep, respectively, but the increases in titre were lower than the homotypic responses, ranging from 10- to 100-fold in most cases and were 1000-fold in two sheep. Interestingly, no heterotypic response against the human rotavirus serotypes was raised after 3 months; moderate titres of cross-neutralizing antibodies for the human serotypes were only observed after a third inoculation.