Fixation of the proximal flange of a lumen-apposing metal stent using a through-the-scope endoscopic suturing system to prevent stent migration in single-session EUS-directed transgastric ERCP: a pilot study.

BACKGROUND AND AIMS: With the global obesity pandemic, clinical scenarios requiring urgent ERCP in patients with gastric bypass surgery are on the rise, and single-session EUS-directed transgastric ERCP (SS-EDGE) can effectively address these technical challenges. The aim of this study was to evaluate and describe the safe and effective use of a through-the-scope endoscopic suturing system for anchoring the lumen-apposing metal stents (LAMSs) during SS-EDGE. METHODS: Six patients with Roux-en-Y gastric bypass (RYGB) underwent SS-EDGE at our center. A through-the-scope endoscopic suturing system was used for anchoring the LAMSs during SS-EDGE. RESULTS: Clinical and technical success was achieved in all 6 patients without any adverse events related to the procedure. No stent migration, pneumoperitoneum, or GI perforation was noted. At the 4-week follow-up, no stent migration was noted, and the through-the-scope suturing system remained anchored. LAMSs along with tacks were removed, and gastric fistulae were successfully closed endoscopically in all patients to prevent weight gain. CONCLUSIONS: Use of through-the-scope endoscopic suturing can be a safe, reliable, and potentially cost-effective novel technique for LAMS fixation to successfully perform SS-EDGE in RYGB patients.

Bacterial allelopathy: An approach for biological control of weeds.

Weed infestation is one of the most damaging biotic factors to limit crop production by competing with the crop for space, water, and nutrients. Different conventional approaches are being used to cope with weed infestation including labor intensive manual removal and the use of soil-degrading and crop-damaging, and environment-deteriorating chemical herbicides. The use of chemicals for weed control has increased two-fold after the Green Revolution and their non-judicious use is posing serious threats to mankind, animals, and biodiversity. The detrimental effects of these approaches have shifted the researchers' attention from the last two decades towards alternate, sustainable, and ecofriendly approaches to cope with weed infestation. The recent approaches of weed control including plant and microbial allelopathy have gained popularity during last decade. Farmers still use conventional methods, but the majority of farmers are very passionate about organic agriculture and describe it as a slogan in the developed world. The effectiveness of these approaches lies in host specificity by selective bacteria and differential response towards weeds and crops. Moreover, the crop growth promoting effect of microorganisms (allelopathic bacteria) possessing various growth promoting traits i.e., mineral solubilization, phytohormone production and beneficial enzymatic activity, provide additional benefits. The significance of this review lies in the provision of a comprehensive comparison of the conventional approaches along with their potential limitations with advanced/biological weed control approaches in sustainable production. In addition, the knowledge imparted about weed control will contribute to a better understanding of biological control methods.

Bacterial secondary metabolites: possible mechanism for weed suppression in wheat.

Chemical weed control is an effective method, but has proved hazardous for humans, environment, and soil biodiversity. Use of allelopathic bacteria may be more efficient and sustainable weed control measure. The bacterial inoculants have never been studied in context of their interaction with weed root exudates and precursor-dependent production of the natural phytotoxins (cyanide, cytolytic enzymes and auxin) by these strains to understand their weed suppression and wheat growth promotion abilities. Therefore, root exudates of Avena fatua, Phalaris minor, Rumex dentatus, and wheat were quantified and their role in microbial root colonization and secondary metabolite production, i.e., cyanide, cytolytic enzymes, phenolics, and elevated auxin concentration, was studied. The results depicted l-tryptophan and glycine as major contributors of elevated cyanide and elevated levels in weed rhizosphere by the studied Pseudomonas strains, through their higher root colonization ability in weeds as compared with wheat. Furthermore, the higher root colonization also enhanced p-coumaric acid (photosynthesis inhibitor by impairing cytochrome c oxidase activity in plants) and cytolytic enzyme (root cell wall degradation) concentration in weed rhizosphere. In conclusion, the differential root colonization of wheat and weeds by these strains is responsible for enhancing weed suppression (enhancing phytotoxic effect) and wheat growth promotion (lowering phytotoxic effect).

The Landscape of Stem Cell Research in Pakistan.

Objectives: The present study is a scoping review of the progress of the field of stem cell research (SCR) in Pakistan in the last two decades. METHODS: Data was extracted from electronic search engines, international clinical trial registry platforms, and PubMed and presented in tabular and graphical form. RESULTS: China, India and Iran are investing heavily in SCR. In Pakistan, reasonable growth in terms of the number of publications is observed in this area, however, clinical translation of the field does not demonstrate any considerable progress. The Government of Pakistan has developed the regulatory framework and initiated preliminary policymaking, adopting rules from international regulatory agencies like World Health Organization (WHO) and Federal Drug Authority (FDA), however, further clarity and policymaking are needed to address the growing trend of stem cell tourism in the country. CONCLUSIONS: The field of SCR is still in its infancy in Pakistan, and needs improvement; scientists, academia, policymakers, and funding agencies must come together to foster high-impact stem cell research in the country. This will aid in elevating the economic burden of many incurable diseases in the country. The outcomes of this study will be helpful for policymakers in their decision-making process.

Safety of glucose-6 phosphate dehydrogenase deficient donors in living right lobe liver donation.

BACKGROUND: The literature lacks data on World Health Organization (WHO) class II and III deficient liver donors who underwent right hepatectomy during living donor liver transplantation (LDLT). METHODS: In this prospective cohort study, we compared the perioperative outcomes of 15 glucose-6 phosphate dehydrogenase (G6PD) deficient living liver donors with a matched cohort of 39 nondeficient living liver donors undergoing right lobe donation. RESULTS: Out of 15 G6PD deficient donors, four (26.67%) donors had class II, and 11 (73.34%) had class III G6PD deficiency. The mean postoperative trough hemoglobin level was significantly lower in the deficient group than the nondeficient group (9.38 ± 1.59 g/dL vs. 10.27 ± .91 g/dL, p = .046). The mean peak indirect bilirubin level was significantly higher in the deficient group than the nondeficient group (2.22 ± 1.38 mg/dL vs. 1.40 ± .89 mg/dL, p = .047), and a similar trend was observed in total serum bilirubin (3.99 ± 2.57 mg/dL vs. 2.99 ± 1.46 mg/dL, p = .038). Biochemical evidence of hemolysis was found only in three (20%) deficient donors, but none of them needed a blood transfusion. No mortality was observed in either group. All other parameters, including demographics, operative parameters, graft characteristics, and hospital stay were comparable between both groups (p > .05). CONCLUSION: G6PD deficiency with WHO class II and above should not be considered a contraindication for right lobe donation.

Is it safe to perform total arterial grafting in elderly patients lacking vein grafts? A single surgeon comparison.

OBJECTIVES: The results of coronary artery bypass graft (CABG) surgery with total arterial revascularisation (TA-CABG) in elderly patients, who may have insufficient vein graft material for conventional CABG (CO-CABG), have not been fully established. We therefore sought to compare the short- and long-term outcomes of patients >70 years old undergoing CO-CABG and TA-CABG. METHODS: We performed a retrospective observational study analyzing all consecutive adult patients aged >70 years undergoing first-time CABG over the 15-year period from 2004 to 2020 under a single surgeon. Primary outcomes of interest were in-hospital mortality, long-term mortality, and re-intervention rate. Secondary outcomes of interest included operative durations and the incidence of peri-operative complications. RESULTS: There were 46 patients (age 76 ± 3 SD) in the TA-CABG group and 145 patients (age 76 ± 4 SD) in the CO-CABG group. Cardio-pulmonary bypass and cross-clamp durations were comparable between groups (p = .11 and p = .23, respectively). Stroke occurred in 1.0% undergoing CO-CABG compared to 0% in the TA-CABG group (p = .42). Hospital mortality was 3.0% with CO-CABG (EuroSCORE; mean [SD] 6.81 (5.81)) and 2.0% with TA-CABG (EuroSCORE; mean [SD] 6.38 (6.57)) (p = .93). On long-term follow-up, myocardial infarction occurred in 10.0% of CO-CABG patients compared to 4.0% of TA-CABG patients (p = .25). Re-intervention rates were 7% following CO-CABG, and 2% after TA-CABG (p = .23). There was no significant difference in long-term mortality between patients undergoing CO-CABG and TA-CABG (47% vs. 57%, p = .27). Long-term survival was comparable between grafting techniques (p = .27). CONCLUSIONS: There were no significant differences in major adverse cardiac and cerebrovascular events, re-intervention rate, hospital or long-term mortality between CO-CABG and TA-CABG. TA-CABG represents a safe and feasible alternative to CO-CABG in elderly patients offering good long-term outcomes.

Surgical management and long-term follow-up of aberrant right coronary arteries in adults.

OBJECTIVES: Anomalous origins of the right coronary artery (RCA) can cause ischaemia and sudden cardiac death, particularly if the RCA runs between the aorta and pulmonary artery. Conventional coronary artery bypass grafting (CABG) can be affected by early graft failure due to collateral blood flow. We present our institutional experience in managing patients with RCA anomalies. METHODS: A single-center retrospective review of all patients who underwent surgery for aberrant right coronary arteries between 2005 and 2021 was conducted and in-hospital and long-term outcomes were analysed at our institution. RESULTS: A total of 10 patients (5 females, median age: 51 years, 36-62) were identified. They presented with symptoms of chest pain (n = 8), dyspnoea (n = 1) or following cardiac arrest (n = 1). In the majority the RCA originated from the left coronary sinus (n = 9). In one of those patients and one in whom the RCA originated directly from the left anterior descending artery CABG was performed. The other 8 patients were treated using transfer of the RCA ostium. All patients were discharged home (median hospital stay 5 days, range: 4-10). Four patients experienced post-op atrial fibrillation. No other complications were observed. At a median follow-up of 10 years and 9 months, 9 patients were alive and free from cardiac symptoms. One patient died 3 years postsurgery due to liver failure, unrelated to cardiac disease. CONCLUSIONS: In patients with an aberrant RCA, transfer of the ostium into the RCS carries a low surgical risk. It overcomes early graft failure in these patients, who present with a dynamic impairment in RCA blood flow. However, if fixed proximal RCA flow-limiting pathology exists, conventional bypass surgery is feasible.

An unusual case of clavicular prosthesis migration causing traumatic injury to the ascending aorta.

Traumatic aortic injuries can be a lethal event. Almost 88% of patients with traumatic aortic injuries die within the first hour and only 2% survive long enough to develop a chronic aneurysm. Injury to the ascending aorta, whether acute or chronic, are typically managed with surgery, and those in the descending aorta, are managed conservatively or in some cases with stents. We present a rare case of a 53-year old gentleman with intra-aortic migration of a left clavicular prosthesis used for restoration of the left shoulder girdle.

Femoral versus axillary cannulation in acute type A aortic dissections: A meta-analysis.

OBJECTIVE: There has been a growing interest in antegrade cannulation techniques in type A aortic dissection surgery. Axillary cannulation has previously been reported to provide better outcomes in terms of short-term mortality and neurological event. Consensus regarding the best cannulation strategy still remains controversial. METHOD: The MEDLINE and EMBASE databases were conducted up until October 3, 2020. Data regarding mortality, stroke, reoperation for bleeding and length of hospital stay, wound infection and cardiopulmonary bypass time were extracted and submitted to a meta-analysis using random-effects modelling and the I2 -test for heterogeneity. Fourteen retrospective observational studies were included, enrolling a total of 2621 patients. RESULTS: There were a total of 2621 patients (1327 axillary cannulation and 874 femoral cannulation). Axillary cannulation was associated with reduced short term mortality (pooled odds ratio [OR] = +0.42, 95% confidence interval [CI] = +0.25 to +0.70; p = .0009) compared to femoral cannulation. Axillary cannulation was also associated with a lower incidence of neurological events (pooled OR = +0.63, 95% CI = +0.42 to +0.94; p = .02). CONCLUSION: Our meta-analyses suggests that axillary cannulation has superior outcomes in terms of mortality and stroke following emergency surgery for type A aortic dissection. However, the lack of high quality randomized controlled trials does not make this recommendation generalisable to all units.

Subtle aortic dissection in a patient with severe aortic regurgitation and undiagnosed bicuspid aortic valve: A case report with a literature review.

BACKGROUND AND AIM OF THE STUDY: A subtle aortic dissection can be challenging to detect despite the availability of multiple diagnostic modalities. Whilst rare, the inability to detect this variant of aortic dissection can lead to a dismal prognosis. We present an extremely rare case of a subtle aortic dissection with supra-annular aortic root intimal tear and acute severe aortic regurgitation in a patient with a bicuspid aortic valve. METHODS: Case report and literature review conserning subtle aortic dissection is provided. RESULTS: Initial concerns were either aortic dissection or infective endocarditis. Despite advanced multimodality preoperative imaging, diagnosis was made intraoperatively and a Bentall procedure with a mechanical aortic valve was performed. CONCLUSIONS: Our case along with the review of current literature emphasizes that current imaging techniques may be inadequate for diagnosis of this rare variant of aortic dissection.

Acute aortic dissection type A: Impact of aortic specialists on short and long term outcomes.

OBJECTIVES: Acute aortic dissection type-A (AADA) is a life threatening condition which requires emergency surgery. Surgery is usually performed by cardiac surgeons with various levels of aortic surgical experience. We compared the short-term perioperative outcome and long-term survival of patients operated by specialist aortic surgeons (SASs)and those who were operated by surgeons without specialist expertise. METHODS: A single center retrospective review of 232 patients who underwent acute surgery for AADA was conducted between 2005 and 2020. The cohort was divided into those operated on by SASs (Group A, n = 186) and those operated on by nonaortic surgeons (Group B, n = 46). Statistical comparison was done using regression modelling and groups were propensity matched. Kaplan-Meier comparison was undertaken using STATA14. RESULTS: Of 232 patients, 186 were operated on by an aortic specialist and 46 were operated by a nonaortic specialist. Overall 30-day mortality was 10% in Group A compared to 26.0% in Group B (unadjusted: p = .01, multivariate: p = .02, and propensity matched p = .05). Long-term mortality at 14 years was 26% in Group A compared to 52.0% in Group B (unadjusted: p = .001, multivariate: p = .001, and propensity matched: p = .01). Aortic surgeons performed a significantly higher number of aortic root procedures (43.0% vs. 17.3%, p = .001). The cross-clamp time and bypass time was significantly shorter in Group A patients (89 vs. 105 min, p < .01 and 153 vs. 185, p = < .001). Postoperative requirement for renal filtration was (19% vs. 37%, unadjusted p = .01, multivariate p = .03 and propensity matched p = .04). Although postoperative bleeding was less in Group A (4.0% vs. 11.0%, unadjusted p = .05) after propensity matching it was not statistically significant. CONCLUSIONS: In patients with AADA, surgery performed by aortic specialist's results in improved outcomes. Aortic specialists replaced more of dissected aorta, resulting in an increased number of complex procedures, which may explain improved long-term survival after AADA in this cohort. This study adds further support in establishing a specialist aortic surgical service in cardiac centers.

Concomitant cardiac surgery and liver transplantation: an alternative approach in patients with end stage liver failure?

BACKGROUND: The results of cardiac surgery in patients with end-stage-liver-disease (ESLD) are poor. Concomitant cardiac surgery and orthotopic liver transplantation (OLT) may be an alternative treatment strategy in these patients. METHODS: Between 2001 and 2018, eight patients underwent concomitant cardiac surgery and OLT (Conc_OLT) in our institution. We analyzed their preoperative, intraoperative and postoperative data and compared them to seven high risk patients with ESLD who underwent isolated cardiac surgery (Iso_Surg). RESULTS: The two groups were not significantly different in terms of gender and age (Conc_OLT: 5 males, 55 ± 15 years, Iso_Surg: 4 males, 60 ± 10 years). Causes for ESLD were primary biliary cirrhosis (Conc_OLT = 1, Iso_Surg = 1), alcoholism (Conc_OLT = 2, Iso_Surg = 2), viral hepatitis (Conc_OLT = 2, Iso_Surg = 2), cryptogenic (Conc_OLT = 2, Iso_Surg = 1), ischemic (Conc_OLT = 1) and hepatocellular carcinoma (Iso_Surg = 1). Model for End-stage-Liver-Disease (MELD) Score (Conc_OLT = 14, Iso_Surg = 13) and Child-Pugh Score (Conc_OLT = 9.5, Iso_Surg = 8) were not significantly different between the two groups. Median logistic European System for Cardiac Operative Risk Evaluation (EuroSCORE) was 9.5% (Conc_OLT) and 7.1% (Iso_Surg). Cardiac procedures undertaken were aortic valve replacement (Conc_OLT = 6, Iso_Surg = 3), coronary bypass grafting (Conc_OLT = 1,Iso_Surg = 2), tricuspid valve repair (Conc_OLT = 1), combined aortic and mitral valve replacement (Iso_Surg = 1) and excision of atrial myxoma (Iso_Surg = 1). Median length of in-hospital-stay was longer in the Conc_OLT group (73 vs. 42 days; p = 0.11). At 3 months, in-hospital mortality was 25% in the Conc_OLT group (n = 2) and lower compared to 71% observed in the Iso_Surg group (n = 5, p = 0.13). CONCLUSION: Concomitant cardiac surgery and OLT is a promising alternative compared to isolated cardiac surgery in high risk patients with ESLD. Given the high operative mortality of cardiac surgery in patients with ESLD, the complex peri-operative management of these patients should be performed in an interdisciplinary team with an expert team of liver specialists involved.

Efficacy of rhizobacterial exopolysaccharides in improving plant growth, physiology, and soil properties.

The current study investigated the influence of exopolysaccharides (EPSs) producing plant growth-promoting rhizobacteria (PGPR) on the growth, physiology, and soil properties. The pre-isolated and compatible EPS producing PGPR strains were first screened based on improvement in soil aggregates in an incubation study. The screened strains (Rhizobium phaseoli strain Mn-6, Pseudomonas bathysetes strain LB5, and unidentified strain R2) were then employed in pot study for assessing improvements in maize growth, physiology, and soil properties. Eight treatments including T1 = control, T2 = Mn-6, T3 = R2, T4 = LB5, T5 = Mn-6 + R2, T6 = Mn-6 + LB5, T7 = R2 + LB5, and T8 = Mn-6 + R2 + LB5 were applied in completely randomized design (CRD) hexa replicated (half for root and half for soil, and yield attributes). The results depicted that among various treatments, the application of PGPR strain Mn-6 increased plant height, root length, root fresh and dry weight, root length density, SPAD value, leaf areas index, photosynthesis rate, transpiration, and stomatal conductance by 24, 79, 72, 90, 49, 35, 23, 21, 75, and 77%, respectively, compared with non-inoculated treatment. Similarly, significant improvement in maize yield and soil physical properties was also observed in response to the application of EPS-producing PGPR. Therefore, it is concluded that the application of EPS producing PGPR is an effective strategy to improve plant growth, physiology, yield, and soil physical properties. Moreover, EPS-producing PGPR should be exploited in field studies for their potential in improving plant growth and soil properties.

Manifestation and Pathogenesis of Sudden Infant Death Syndrome: A Review.

Historically known as "cot death," sudden infant death syndrome (SIDS) is one of the leading causes of postnatal death in infants. According to the Centers for Disease Control and Prevention in 2010, more than 2,000 U.S. infants died from SIDS. Sudden infant death syndrome is the unexplainable death of an infant, less than one year old, that is otherwise healthy. SIDS was first discovered in 1969, and it typically presents in infants with a peak incidence between 2 and 4 months of age. Death by SIDS is typically more prevalent in the winter months, making the infant increasingly vulnerable. Despite witnessing a significant decrease in deaths by SIDS due to awareness campaigns and medical advancements, SIDS remains the leading cause of infant mortality in Western countries, accounting for half of all postnatal deaths. Throughout this paper, we will focus on the environmental factors, physiological factors, and genetic factors that have been postulated to cause an infant to be susceptible to SIDS. The initially postulated pathogenesis of SIDS was explained as the triple risk hypothesis, which states that an increase in SIDS risk presents in situations where there is an overlap of three or more factors. The presence of three or more factors suggests that the trio of factors overrule the infant's threshold for survival; therefore, the infant's homeostasis is unable to protect against the dangers. Death by SIDS has declined considerably from 130.3 deaths per 100,000 live births in 1998 to 38.7 deaths per 100,000 live births in 2014.

Prosthetic aortic valve endocarditis complicated by COVID-19 and hemorrhage.

The novel coronavirus, now termed SARS-CoV-2, has caused a significant global impact in the space of 4 months. Almost all elective cardiac surgical operations have been postponed with only urgent and emergency operations being considered in order to maximise resource utilisation. We present a case of a 69-year old lady with an infected prosthetic aortic valve for consideration of urgent inpatient surgery. Despite being asymptomatic and testing negative initially for COVID-19 RT-PCR swab, further investigations with CT revealed suspicious findings. She subsequently tested positive on a repeat swab and unfortunately deteriorated rapidly with complications including gastro-intestinal and intracerebral haemorrhage.

Cardiac surgery in patients with confirmed COVID-19 infection: Early experience.

The novel coronavirus, now termed SARS-CoV-2, has caused a significant global impact in the space of 4 months. Almost all elective cardiac surgical operations have been postponed in order to reduce transmission and to allocate resources adequately. Urgent and emergency cardiac surgery is still taking place during the pandemic. The decision to operate in urgent patients with active/recent COVID-19 infection is difficult to make, particularly as it is still an unknown disease entity in the setting of emergent cardiac surgery. We present a case series of three patients who underwent urgent cardiac surgery and who have had recent or active COVID-19 infection.

The Pan London Emergency Cardiac Surgery service: Coordinating a response to the COVID-19 pandemic.

Over the last 4 months, the novel coronavirus, SARS-CoV-2, has caused a significant economic, political, and public health impact on a global scale. The natural history of the disease and surge in the need for invasive ventilation has required the provision of intensive care beds in London to be reallocated. NHS England have proposed the formation of a Pan-London Emergency Cardiac surgery (PLECS) service to provide urgent and emergency cardiac surgery for the whole of London. In this initial report, we outline our experience of setting up and delivering a pan-regional service for the delivery of urgent and emergency cardiac surgery with a focus on maintaining a COVID-free in-hospital environment. In doing so, we hope that other regions can use this as a starting point in developing their own region-specific pathways if the spread of coronavirus necessitates similar measures be put in place across the United Kingdom.

Cadmium mediated phytotoxic impacts in Brassica napus: Managing growth, physiological and oxidative disturbances through combined use of biochar and Enterobacter sp. MN17.

Cadmium (Cd) is a toxic heavy metal with unknown biological role. Interactive effect of Enterobacter sp. MN17 and biochar was studied on the growth, physiology and antioxidant defense system of Brassica napus under Cd contaminated soil. A multi-metal tolerant endophytic bacterium, Enterobacter sp. MN17, was able to grow in tryptic soy agar (TSA) medium with up to 160, 200, 300, 700, 160 and 400 µg mL-1 of Cd, Cu, Cr, Pb, Ni and Zn, respectively. Paper and pulp waste biochar was prepared at 450 °C and applied to pots (7 kg soil) at a rate of 1% (w/w), while Cd was spiked at 80 mg kg-1 soil. Application of Enterobacter sp. MN17 and biochar, alone or combined, was found effective in the amelioration of Cd stress. Combined application of Enterobacter sp. MN17 and biochar caused the maximum appraisal in shoot and root length (52.5 and 76.5%), fresh and dry weights of shoot (77.1 and 70.7%) and root (81.2 and 57.9%), photosynthetic and transpiration rate (120.2 and 106.6%), stomatal and sub-stomatal conductance (81.3 and 75.5%), chlorophyll content and relative water content (RWC) (78.4 and 102.9%) than control. Their combined use showed a significant decrease in electrolyte leakage (EL), proline, malondialdehyde (MDA), catalase (CAT), glutathione peroxidase (GPX), glutathione S transferase (GST) and superoxide dismutase (SOD) by 39.3, 39.4, 39.5, 37.0, 39.0 42.1 and 30.8%, respectively, relative to control. Likewise, the combined application of bacterial strain MN17 and biochar reduced Cd in soil by 45.6%, thereby decreasing its uptake in root and shoot by 40.1 and 38.2%, respectively in Cd contaminated soil. The application of biochar supported the maximum colonization of strain MN17 in the rhizosphere soil, root and shoot tissues. These results reflected that inoculation with Enterobacter sp. MN17 could be an effective approach to accelerate biochar-mediated remediation of Cd contaminated soil for sustainable production of crops.

Exopolysaccharides and indole-3-acetic acid producing Bacillus safensis strain FN13 potential candidate for phytostabilization of heavy metals.

Microbial population of soils irrigated with industrial wastewater may contain certain exopolysaccharides (EPS) and indole-3-acetic acid (IAA) producing bacterial strains having the ability to tolerate heavy metals along with plant growth-promoting (PGP) traits. As cadmium is one of the most toxic heavy metals for soils, plants, animals, and human beings, the present study was planned to isolate and characterize EPS- and IAA-producing, Cd-tolerant bacterial strains having tolerance against heavy metals along with plant growth-promoting traits. A total of 30 rhizobacterial strains (FN1-FN30) were isolated from rhizosphere soil collected from fields around industrial areas and roadsides irrigated with industrial wastewater. Out of these, eight isolates with the combined ability of IAA production and EPS production were characterized for PGP traits. On the basis of multifarious PGP traits and the results of root colonization assay, three most efficient EPS- and IAA-producing, Cd-tolerant plant growth-promoting strains, i.e., FN13, FN14, and FN16, were selected for multiple metal (Cd, Pb, Ni, and Cu) tolerance test along with quantification of growth, and IAA and EPS production abilities under Cd stress. Increasing levels of Cd stress negatively affected the tested characteristics of these strains, but FN13 showed more stability in growth, IAA production (18.24 µg mL-1), and EPS production (148.99 µg mL-1) compared to other strains under Cd stress. The morphological and biochemical analysis confirmed FN13 as Gram-positive, rod-shaped bacteria with smooth colonies of yellow appearance. The strain FN13 has strong root colonization (3.36 × 106 CFU g-1) ability for mustard seedlings and can solubilize Zn and phosphate along with the production of HCN, ammonia, and siderophores. The 16S rRNA sequencing confirmed it as the Bacillus safensis strain FN13. It can be explored as potential phytostabilizing biofertilizer for heavy metal-contaminated soils.

Role of biochar and plant growth promoting rhizobacteria to enhance soil carbon sequestration-a review.

Global climate is undergoing significant changes due to extensive release of greenhouse gases (GHGs) such as CO2 and methane in the atmosphere. These gases are produced and released as a result of anthropogenic activities and fossil fuel burnings which also result in depletion of soil carbon resources. Biochar has various distinctive properties, which contribute to make it an effective, economical, and eco-friendly approach for soil carbon sequestration. The versatility in physicochemical properties of biochar provides an opportunity to optimize its efficacy to obtain desired benefits. A critical review of the literature indicates that biochar and plant growth-promoting microbes have the potential to improve soil organic carbon (SOC). Recent studies have depicted a significant role of the combined application of plant growth-promoting microbes and biochar on SOC dynamics. In future, these areas need to be explored as these have the potential to improve SOC dynamics and it could be a better strategy to sustain natural resources and ultimately mitigation of the climate change.