The present investigation highlights the process parameters influencing the submerged fermentation of chitinase by Bacillus pumilus JUBCH08, purification and characterization of the enzyme and determination of antagonistic activity of the bacterium against Fusarium oxysporum. Medium supplemented with 0.5 % chitin and peptone, at initial pH 8.0, when incubated at 35 °C for 72 h favored highest chitinase production. The enzyme was purified 25.1-fold to homogeneity. The chitinase was found to be thermostable and alkali-tolerant with maximum activity at pH 8.0 and 70 °C for 1 h. The molecular weight of chitinase was found to be 64 kDa by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Mg2+, Co2+, Ca2+ and Mn2+ improved the chitinase activity. The K m and V max values of the enzyme were 0.13 mg/ml and 38.23 U/ml, respectively. When subjected to dual plate assay, the bacterium showed 45 % antagonism against F. oxysporum. Thus, it could be inferred that cultural conditions strongly affected the chitinase production by B. pumilus JUBCH08. The enzyme being thermostable and best functional under alkaline conditions could be useful for the feed industry and related biotechnological applications. Inhibition of F. oxysporum by the culture through lytic mechanism indicates its potentiality as a biocontrol agent.

Background: Coronavirus disease 2019 (COVID19) is a highly infectious disease responsible for huge number of deaths in global population. Bronchoscopy was contraindicated for acute respiratory failure in critical patients due to possible transmission of virus to healthcare provider due to aerosol generating procedure (AGP). The safety, efficacy, complication rate, deaths, and transmission rate of virus to healthcare workers due to therapeutic and interventional bronchoscopy performed on COVID19 patients are accessed. Methods: A systematic review of literature was performed as per PRISMA 2020 guidelines. To obtain literatures available in PubMed, MEDLINE, and Google Scholars with timeline from 1st Jan 2020 to 10th Dec 2021. Databases were searched with MeSH terms bronchoscopy and COVID-19 it fetched 7350 articles. Applying primary inclusion criteria of bronchoscopy in COVID19 patients. Secondary inclusion criteria therapeutic and interventional bronchoscopy excluding the articles on diagnostic bronchoscopy. Result: Total 72 clinically relevant literatures were identified and included for further review. 1887/2558 patients underwent bronchoscopy for treatment of severe or critical COVID19 pneumonia. therapeutic bronchoscopy was performed in 1241/1887 (65.8%) patients and interventional bronchoscopy was performed in 831/1887 (44.03%) patients. Overall, complications observed in 200/1887 (10.5%) patients. Total, 579/1887 (30%) patients died as per the literatures. Total 15 HCW (8%) were found infected during the studies. It led to successful completion of procedures in 924/940 (98.3%) patients. All three types of bronchoscopes were found to be safe for the patients. The safety, efficacy, complication rate to be 97.5%, and 98.3%, and 2.5% respectively in severely SARSCoV2 infected patients undergoing bronchoscopy. Conclusion: This study suggests that bronchoscopy is a safe and effective procedure to be performed in patients suffering from COVID19 pneumonia. Proper use of personal protective equipments (PPE) during bronchoscopic procedure reduced the risk of transmission of the virus from the patients to the healthcare provider.