A review on nitrogen dynamics and mitigation strategies of food waste digestate composting

Food waste digestate is a by-product of the anaerobic digestion of food waste. Presence of high ammonium nitrogen content significantly increase the nitrogen loss upon direct application on soil or by conventional composting. In this review, a comprehensive discussion regarding the effective management of food waste digestate is outlined, in which global food waste digestate production, characteristics, and composting are discussed. The nitrogen dynamics cycle considering high ammonium nitrogen content in the digestate is also evaluated, including ammonification, nitrification, denitrification, and other possible mechanisms based on the current literature. Mitigation strategies for reducing nitrogen loss via C/N ratio adjustment and the addition of physical, chemical, and microbial amendments were evaluated and estimated for 15 countries based on the available data on food waste anaerobic digestion plants. Reduced nitrogen loss and high quality compost could be produced from food waste digestate by adapting mitigation strategies.

Performance assessment of improved composting system for food waste with varying aeration and use of microbial inoculum

Wet waste recycling at generation point will alleviate burden on the overflowing waste dumpsites in developing nations. Drum composting is a potential treatment option for such waste at individual or community level. The present study was aimed to produce compost from wet waste (primarily comprising food waste) in composting drums modified for improved natural air circulation. Effect of microbial inoculum and waste turning on composting process was also studied. The final results showed the production of matured and stable compost in the modified drums. Addition of the microbial inoculum resulted in thermophilic phase within a week time. The self-heating test and germination index (>80%) showed the production of non-phytotoxic and mature compost in the modified drums after 60days. The change in microbial population, humic substances and biological parameters (lignin, cellulose and hemicellulose) during the study is discussed. Moreover, the reduction in waste mass and volume is also reported.

Food waste digestate composting: Feedstock optimization with sawdust and mature compost

Direct land application of food waste digestate (FWD) leads to 60-70% of nitrogen loss through NH₃ volatilization due to its innate characteristics like high ammonium nitrogen (NH₄⁺-N) (~6000 mg/kg dry matter) and high moisture content (~75%). Hence, bio stabilization of FWD through composting is a promising solution to curb the environmental and occupational hazards. Hence the aim of this study was to assess the feasibility of using sawdust and/or mature compost as a bulking agent to achieve effective composting. The results showed that mixing of FWD with sawdust alone or together with mature compost could produce quality compost with reduced NH₄⁺-N (<700 mg/kg dry matter) and increased seed germination index (>80%) within 2 weeks of co-composting. Composting FWD with both sawdust and mature compost effectively reduced ~ 83% of NH₃ volatilization demonstrating that this approach can effectively produce mature nitrogen enriched FWD compost.

Biodegradation kinetics of ammonium enriched food waste digestate compost with biochar amendment

High concentration of NH₄⁺-N in food waste digestate (FWD) produced from biological treatment of food waste is considered as a major threat on the composting process resulting in production of immature compost. Hence, a laboratory batch composting study was conducted to examine the feasibility of using biochar as a physical additive to ameliorate the inhibitory effect of NH₄⁺-N and to mitigate the nitrogen loss during FWD composting. FWD was co-composted with tobacco biochar at a dosage of 0%, 2.5%, 5% or 10% (dw) in bench-scale composters with a controlled aeration system. The addition of 10% biochar enhanced the degradation rate resulting in 44% higher carbon decomposition than the control. Besides, 10% biochar amendment reduced NH₃ and N loss by 58% and 5%, respectively and significantly reduced NH₄⁺-N content to HKORC limit of < 700 mg/kg dw within 5 days showing the beneficiary impact of biochar addition.

Population-based cohort study of variation in the use of emergency cholecystectomy for benign gallbladder diseases

Background

The aims of this prospective population-based cohort study were to identify the patient and hospital characteristics associated with emergency cholecystectomy, and the influences of these in determining variations between hospitals.

Methods

Data were collected for consecutive patients undergoing cholecystectomy in acute UK and Irish hospitals between 1 March and 1 May 2014. Potential explanatory variables influencing the performance of emergency cholecystectomy were analysed by means of multilevel, multivariable logistic regression modelling using a two-level hierarchical structure with patients (level 1) nested within hospitals (level 2).

Results

Data were collected on 4744 cholecystectomies from 165 hospitals. Increasing age, lower ASA fitness grade, biliary colic, the need for further imaging (magnetic retrograde cholangiopancreatography), endoscopic interventions (endoscopic retrograde cholangiopancreatography) and admission to a non-biliary centre significantly reduced the likelihood of an emergency cholecystectomy being performed. The multilevel model was used to calculate the probability of receiving an emergency cholecystectomy for a woman aged 40 years or over with an ASA grade of I or II and a BMI of at least 25·0 kg/m2, who presented with acute cholecystitis with an ultrasound scan showing a thick-walled gallbladder and a normal common bile duct. The mean predicted probability of receiving an emergency cholecystectomy was 0·52 (95 per cent c.i. 0·45 to 0·57). The predicted probabilities ranged from 0·02 to 0·95 across the 165 hospitals, demonstrating significant variation between hospitals.

Conclusion

Patients with similar characteristics presenting to different hospitals with acute gallbladder pathology do not receive comparable care.

Mitigation of NH3 and N2O emissions during food waste digestate composting at C/N ratio 15 using zeolite amendment

Composting of food waste digestate (FWD) is challenging as it requires more bulking agents, and the nitrogen loss is inevitable. To address these issues, FWD composting was conducted at a relatively lower C/N ratio of 15 with zeolite amendment in the dosage range of 5-15%. The impact of zeolite addition on nitrogen loss, NH₃ and N₂O emissions was assessed during FWD composting. The results showed that the addition of 10-15% zeolite could significantly reduce the phytotoxic nature of FWD and the compost maturity level could be reached in 10-21 days. Furthermore, ∼45% total nitrogen loss could be reduced by mitigating NH₃ and N₂O emissions upon 10 and 15% zeolite amendment. The outcome of the present study could be used as an effective strategy for composting FWD in any part of the world as the FWD characteristics are similar irrespective of the type of food waste.

Evaluation of surgical outcome scores according to ISGPS definitions in patients undergoing pancreatic resection

AIMS

To evaluate the role of the Physiological and Operative Severity Score for the enUmeration of Mortality and Morbidity (POSSUM), the Portsmouth variant (p-POSSUM) and the Glasgow Prognostic Score (GPS) in predicting outcome after pancreatic surgery with reference to the International Study Group of Pancreatic Surgery (ISGPS) definitions of post-pancreatectomy complications.

METHODS

All consecutive patients undergoing major pancreatic resection over a 32- month period were included. POSSUM, p-POSSUM and GPS score were calculated for each patient and correlated against the observed mortality and morbidity using the ISGPS definitions.

RESULTS

The observed:expected ratios for POSSUM mortality, POSSUM morbidity and p-POSSUM mortality were 0.24 (p < 0.0001), 0.86 (p < 0.0001) and 0.79 (p = 0.09), respectively. POSSUM had a 'poor fit' with respect to predicting morbidity (χ(2) = 16.4, 8 d.f., p = 0.04). Multifactorial regression analysis revealed the GPS as an independent predictor of post-operative outcome (GPS 1, p = 0.03, OR 2.99, 95% CI 1.4-7.9, and GPS 2, p = 0.02, OR 4.3, 95% CI 1.8-15.5).

CONCLUSION

POSSUM has a limited role as an outcome score in pancreatic resection. The GPS may be a novel alternative to POSSUM as a pre-operative predictor of outcome.

Role of tobacco and bamboo biochar on food waste digestate co-composting: Nitrogen conservation, greenhouse gas emissions, and compost quality

Anaerobic digestion is considered an environmentally benign process for the recycling of food waste into biogas. However, unscientific disposal of ammonium-rich food waste digestate (FWD), a by-product of anaerobic digestion induces environmental issues such as odor nuisances, water pollution, phytotoxicity and pathogen transformations in soil, etc. In the present study, FWD produced from anaerobic digestion of source-separated food waste from markets and industries was used for converting FWD into biofertilizer using 20-L bench scale composters. The issues of nitrogen loss, NH₃ volatilization, and greenhouse gas N₂O emission were addressed using in-situ composting technologies with the aid of tobacco and bamboo biochar produced at pyrolytic temperatures of 450 °C and 600 °C, respectively. The results demonstrated that the phytotoxic nature of FWD could be reduced into a nutrient-rich compost by mitigating nitrogen loss by 29-53% using 10% tobacco and 10% bamboo biochar in comparison with the control treatment. Tobacco biochar mitigates NH₃ emission by 63% but enhances the N₂O emission by 65%, whereas bamboo biochar mitigates both NH₃ and N₂O emissions by 48% and 31%, respectively. Overall, 10% tobacco and 10% bamboo biochar amendment could reduce total nitrogen loss by 29% and 53%, respectively. Furthermore, the biochar addition significantly enhanced the biodegradation rate of FWD and the mature compost could be produced within 21 days of FWD composting as seen by an increased seed germination index (>50% on dry weight basis). The results of this study could be beneficial in developing a circular bioeconomy locally with the waste-derived substrates.

Molecular technology and pancreatic cancer

BACKGROUND

Pancreatic cancer is the fifth leading cause of cancer death in the Western world. Despite improvement in operative mortality rates, little impact has been made on overall 5-year survival. This review discusses the molecular changes peculiar to pancreatic cancer and how the use of molecular technology might affect detection, screening, diagnosis and treatment of the disease.

METHODS

A literature review was performed using the National Library of Medicine's Pubmed database; this was combined with ongoing work within the Queen Elizabeth Hospital, Birmingham.

RESULTS

Over the past 20 years great strides have been made in our understanding of the molecular basis of disease. Advances in molecular biology are now reshaping how diseases are screened for, diagnosed, investigated and treated. In recent years collaboration between clinicians and basic scientists has revealed a unique pattern of genetic and molecular events in pancreatic cancer. This review discusses how these advances may impact on patients with this disease.

CONCLUSION

The past decade has seen some improvement in outlook for patients with pancreatic cancer, but the 'molecular age' promises to deliver even better results.

Impact of total solids content on biochar amended co-digestion of food waste and sludge: Microbial community dynamics, methane production and digestate quality assessment

This study evaluates the impact of biochar addition on the performance of anaerobic co-digestion of food waste (FW) and sewage sludge at different total solids (TS) contents (2.5 %, 5.0 %, and 7.5 %). Biochar co-digestion improved hydrolysis and acidogenesis by neutralizing volatile fatty acids (VFAs) reducing its inhibitions (2.6-fold removal), which elevated the soluble chemical oxygen demand (sCOD) degradation by 2.5 folds leading to a higher cumulative methane production compared to the control. This increase corresponded to an improvement of methane yields by ∼21 %-33 % (242-340 mL/gVS_add) at different TS contents. The biochar surface area offered substantial support for direct interspecies electron transfer (DIET) activity, and biofilm-mediated growth of methanogens i.e., Methanosarcina, Methanosata, and Methanobrevibacter. The biochar-enriched digestate improved the seed germination index, and bioavailability of plant nutrients such as N, P, K, and NH₄^+-N. This study reports an improved biochar-mediated anaerobic co-digestion for efficient and sustainable FW valorization.

Cardiac Troponin T and creatine kinase MB fraction levels among patients with acute ischemic stroke in Nigeria

BACKGROUND

Stroke has been a global burden, with increasing morbidity and mortality. Serum cardiac troponin t (cTnT) and creatine kinase (CK-MB) fraction are reported to be elevated in patients admitted with acute ischaemic stroke and high level of these biomarkers indicated more severe stroke and neurologic deficit in some of the patients.

OBJECTIVE

To evaluate the serum levels cardiac troponin t (cTnT) and creatine kinase MB fraction (CK-MB) in patients with acute ischaemic stroke and relate the analytes to severity of stroke.

METHOD

Patients with clinical diagnosis of ischaemic stroke diagnosed, confirmed by brain Computerized Tomography scan and equal number of apparently healthy age and sex-matched were recruited. Serum cardiac troponin t (cTnT) and creatine kinase MB fraction (CK-MB) were analysed using ELISA method and Stroke severity was determined using National Institute of Health Stroke Score (NIHSS).

RESULTS

Mean serum cardiac troponin t (cTnT) and creatine kinase MB fraction (CK-MB) in stroke patients were found to be higher than age sex matched control (p<0.05). NIHS Score of 12.2 ± 5.43 and 9.78 ± 3.97 were observed in Patients with elevated and normal cTnT respectively (p=0.009) while NIHS Score were similar in patients with elevated and normal CK-MB (p = 0.772).

CONCLUSION

The mean values of serum cTnT and CK-MB were higher in acute ischaemic stroke patients compared to controls. Serum cardiac Troponin t level may be a significant biomarker of the severity of stroke.

A review on mechanistic understanding of microplastic pollution on the performance of anaerobic digestion

Anaerobic digestion (AD) has emerged as a promising technology for diverting the organic waste from the landfills along with the production of clean energy. AD is a microbial-driven biochemical process wherein the plethora of microbial communities participate in converting the putrescible organic matter into biogas. Nevertheless, the AD process is susceptible to the external environmental factors such as presence of physical (microplastics) and chemical (antibiotics, pesticides) pollutants. The microplastics (MPs) pollution has received recent attention due to the increasing plastic pollution in terrestrial ecosystems. This review was aimed for holistic assessment of impact of MPs pollution on AD process to develop efficient treatment technology. First, the possible pathways of MPs entry into the AD systems were critically evaluated. Further, the recent literature on the experimental studies pertaining to the impact of different types of MPs at different concentrations on the AD process was reviewed. In addition, several mechanisms such as direct exposure of MPs on the microbial cells, indirect impact of MPs through the leaching of toxic chemicals and reactive oxygen species (ROS) formation on AD process were elucidated. Besides, the risk possessed by the increase of antibiotic resistance genes (ARGs) after the AD process due to the MPs stress on microbial communities were discussed. Overall, this review deciphered the severity of MPs pollution on AD process at different levels.

Characterization of defective interfering (DI) particles of Pestedes petitsruminants vaccine virus Sungri/96 strain-implications in vaccine upscaling

The present investigation deals with the characterization of defective interfering (DI) particles of Peste-des-petits ruminants (PPR) vaccine Sungri/96 strain generated as a result of high MOI in Vero cells. During the serial 10 passages, infectivity titres drastically reduced from 6.5 to 2.25 log₁₀TCID₅₀/ml at high MOI. Further, attenuation of CPE with high MOI indicated generation of DI particles that resulted in no/slow progression of CPE during the late passages. Monoclonal antibody based cell ELISA indicated normal protein (N & H) packaging in samples with DI activity. At genomic level, inconsistency in amplicon intensity of H gene was observed in RT-PCR, indicating a possible defect of H gene. Further analysis of copy number of PPRV by RT-qPCR indicated intermittent fluctuations of viral genomic RNA copies. The significant decline of viral RNA copies with MOI 3 (314 copies) compared to low MOI (512804 copies), proved that higher DI multiplicities cause more interference with the replication process of the standard virus. Therefore, MOI is critical for manufacturing of vaccines. These investigations will help in upscaling of PPR vaccines in view of ongoing National and Global PPR control and eradication programme.

Effect of Chinese medicinal herbal residues compost on tomato and Chinese cabbage plants: Assessment on phytopathogenic effect and nutrients uptake

Chinese medicinal herbal residues (CMHRs) are known for their antipathogenic properties due to the presence of bioactive compounds. Hence, CMHRs could be used as a potential resource to produce biofertilizer with antipathogenic properties for agricultural applications. In this study, a novel approach was used by utilizing the waste-derived biofertilizer, i.e., CMHRs compost (CMHRC) as a nutrient supplier as well as an organic bioagent against Alternaria solani (A. solani) and Fusarium oxysporum (F. oxysporum) on tomato (Lycopersicon esculentum) and Chinese cabbage (Brassica rapa subsp. Chinensis) plants. The experiments were conducted under greenhouse conditions using locally collected acidic soil wherein 2%, 5% and 10% CMHRC (dry weight) along with 5% food waste compost were used as treatments. In addition, only soil and soil with phytopathogens were used as control treatments. The results suggested that amending the compost into acidic soil significantly increased the pH to a neutral level along with enhanced uptake of nutrients. Among all the treatments, 5% CMHRs compost addition increased the tomato plant biomass production to 4.9 g/pot (dry weight) compared to 2.2 g/pot in control. A similar trend was observed in Chinese cabbage plants and the improved plant biomass production could be attributed to the combined effect of strong nutrient absorption ability by healthy roots and enhanced nutrient supply. At 5% CMHRC application rate, the nitrogen uptake by tomato and Chinese cabbage plants increased by 78% and 62%, respectively, whereas phosphorous uptake increased by 75% and 25%, respectively. The reduction in A. solani by 48% and F. oxysporum by 54% in the post-harvested soil of 5% CMHRC treatment against the control demonstrated the anti-phytopathogenic efficiency of CMHRC compost. Hence, the present study illustrates the beneficiary aspects of utilizing CMHRs to produce biofertilizer with anti-phytopathogenic properties which can be safely used for tomato and Chinese cabbage plant growth.

Stability of live attenuated classical swine fever cell culture vaccine virus in liquid form for developing an oral vaccine

Classical swine fever (CSF) is an important viral disease of pigs and controlled by vaccination. Unorganised backyard and wild pigs are difficult to vaccinate by needle vaccination. Here we formulated liquid vaccines using an Indian CSF cell culture vaccine virus and four stabilisers and evaluated their stability at 4 °C, 25 °C and 37 °C up to 24 h for use as oral vaccine. The stabilisers were Lactalbumin hydrolysate-Trehalose, Lactalbumin hydrolysate-Trehalose-Gelatin, Lactalbumin hydrolysate-Lactose-Sucrose and Lactalbumin hydrolysate-Sucrose. The liquid vaccines, with or without stabilisers, were stable at 4 °C up to 24 h, whereas, a drop of one log₁₀ titre was observed at 25 °C during the same period. At 37 °C, the virus titre diminished by only one log₁₀ with the Lactalbumin hydrolysate-Trehalose (LT) stabiliser up to 24 h compared to two log₁₀ losses in virus titre with other stabilisers and virus control. We therefore conclude that for developing a CSF oral vaccine, the vaccine virus in liquid form can be used directly during the winter, whereas for developing the oral vaccine for summer, the LT stabiliser would provide maximum stability to the virus to withstand the warm temperature while maintaining adequate therapeutic titre for inducing a protective immune response.

Influence of inoculum-to-substrate ratio on biogas enhancement during biochar-assisted co-digestion of food waste and sludge

High accumulation of volatile fatty acids (VFAs) is one of the major concerns during mesophilic anaerobic co-digestion of food waste (FW) and sewage sludge (SS). Therefore, improving the stability of the anaerobic digestion process could surpass quick acidification while accelerating methanogenesis. In this study, the suitability of biochar-assisted co-digestion was evaluated at different inoculum and substrate ratios (I/S ratios: 0.1, 0.3, 0.6, and 0.9). The maximum methane yield of 256.85 mL/gVSadd was observed at an I/S ratio of 0.6. The results indicated fast volatile solid removal (∼ 47.17% to 73%) and a critical role of biochar addition in alleviating the underlying inhibitions. Substantial changes in the microbial community composition including Methanosata, Methanobrevibacter, and Methanosarcina were also observed which predominated and stabilised the methanogenesis process at higher I/S ratios. These results emphasised that the anaerobic co-digestion of FW/sludge is a promising approach, wherein the biochar amendment at different I/S ratios should be well maintained to avoid inhibitions from excess microbial VFA acidification of organic waste feedstocks.

Impact of a catastrophic flood on the heavy metal pollution status and the concurrent responses of the bentho-pelagic community in a tropical monsoonal estuary

Consequences of a catastrophic flood on the habitat quality and the concurrent responses of the bentho-pelagic community were studied in Cochin estuary, a eutrophic estuary along the southwest coast of India. The episodic flood in 2018 led to a marked decline in the dissolved nutrients and heavy metal concentrations in water and sediments of the estuary. The pre-flood phytoplankton abundance dominated by a bloom-forming species Cerataulina bicornis experienced a significant drop after the flood. Contrarily, zooplankton and macrobenthos responded favorably towards the flood-imposed habitat alterations. Higher susceptibility to heavy metal pollution and increased grazing pressure from gelatinous carnivores restricted the abundance of Copepoda, the dominant zooplankton taxon during pre-flood. The lower heavy metal concentration in the sediment after the flood favored higher macrobenthic abundance and diversity with a conspicuous change in the community structure from opportunistic polychaetes, indicators of pollution to molluscans and crustaceans, indicators of the healthy benthic zones.

Genome-centric polyhydroxyalkanoate reconciliation reveals nutrient enriched growth dependent biosynthesis in Bacillus cereus IBA1

Microbiological polyhydroxyalkanoates (PHAs) are rooted as the most promising bio-replacements of synthetic polymers. Inherent properties of these PHAs further expand their applicability in numerous industrial, environmental, and clinical sectors. To propel these, a new environmental, endotoxin free gram-positive bacterium i.e., Bacillus cereus IBA1 was identified to harbor advantageous PHA producer characteristics through high-throughput omics mining approaches. Unlike traditional fermentations, nutrient enriched strategy was used to enhance PHA granular concentrations by ∼2.3 folds to 2.78 ± 0.19 g/L. Additionally, this study is the first to confirm an underlying growth dependent PHA biogenesis through exploring PHA granule associated operons which harbour constitutively expressing PHA synthase (phaC) coupled with differentially expressing PHA synthase subunit (phaR) and regulatory protein (phaP, phaQ) amid different growth phases. Moreover, the feasibility of this promising microbial phenomenon could propel next-generation biopolymers, and increase industrial applicability of PHAs, thereby significantly contributing to the sustainable development.

A case series of steroid-induced diabetes mellitus in Zaria, Nigeria

INTRODUCTION

New-onset diabetes Mellitus can occur in patients without documented hyperglycaemia before corticosteroid therapy, however hyperglycaemia has been reported as an adverse effect of steroids such as Prednisolone.This may be encountered in the management of haematologic disorders or malignancies when prolong administration or high dose prednisolone is used alone or as an adjuvantto cytotoxic agents

AIM

To report three adults who developed hyperglycaemia following an oral administration of prednisolone and to review the current literature on Steroid-induced diabetes mellitus. Method:We undertook a review of the case records of the three patients and an electronic MEDLINE as well as a manual library search of existing pertinent literature.

RESULT

Three male adults aged 55, 50 and 65 years old developed Diabetes Mellitus following the oral steroid administration. In the first case, oral Prednisolone (60mg/day) was used in combination to a cytotoxic agent Melphalan in the management of a plasma cell dyscrasia (Multiple Myeloma), the second case followed a one week course of same dose of prednisolone for Chronic lymphocytic leukaemia while the third case also had oral prednisolone administered alone for an Autoimmune Haemolytic anaemia. Aging, high body mass index and cumulative doses of steroids may be risk factors for the development of steroid-induced hyperglycaemia. The prevalence of this condition, possible pathogenesis and options for treatment are discussed.

CONCLUSION

Steroid-induced diabetes mellitus is an important clinical finding that, if recognized early, can be effectively treated. We propose Fasting blood sugar and Oral glucose tolerance test as part of the pretreatment investigation during the evaluation as well as in the course of management of middle aged and elderly patients on steroids.