A biosurfactant producing isolate of Stenotrophomonas maltophilia (BR-12) was isolated from crude oilcontaminated soil from Vadodara oil refinery (India) and characterized on the basis of biochemical tests and identified by 16S rRNA sequencing. It was also assessed for its Pyrene bioremediation potential under submerged conditions in minimal media spiked with Pyrene at 20, 50, and 100 lg mL -1 . Analysis of microbial growth parameters revealed that BR-12 grew best at 50 lg mL -1 Pyrene concentration, leading to 87 % degradation of Pyrene within 20 days and production of high amount of biosurfactant (2.2 g L -1 ). Since biosurfactant production ability of bacteria can play a major role in enhancing its ability to degrade Pyrene, this promising strain needs to be further exploited in bioremediation of PAH-contaminated sites.

Statistical trend analysis and time-series prediction model are widely used in water quality regulation. Using the Mann-Kendall test, trend analysis was performed on monthly time series. The monthly findings revealed that only the potential Hydrogen (pH) and Total Coliforms (TC) showed meaningful trends. Future values for the parameters which affect water quality have been predicted using the Autoregressive Integrated Moving Average (ARIMA) model. R-square, root mean square error, absolute maximum percentage error, absolute maximum error, normalised Bayesian information criteria, Ljung-Box analysis were used to validate the model. It has been found that the predictive models for potential Hydrogen (pH), Dissolved Oxygen (DO), Biochemical Oxygen Demand (BOD), and Total Coliforms (TC) are useful at 95% confidence limits. Also, the results showed that the pH values will be in the range of 7.2 to 7.5 and the predicted series were similar to the original series, providing a perfect fit. The DO (mg/l) ranges from 7.8 to 12.3 mg/l. BOD (mg/l) fluctuates continuously between 1.2 and 1.3 mg/l. The TC (MPN/100ml) values show reducing trend. The study show that the quality of water is deteriorating based on the trend for the parameters and needs managerial actions.