Since 60-80% of total costs of production are usually associated with downstream collection, separation, and purification processes, it has become advantageous to investigate how to replace traditional methods with efficient and cost-effective alternative techniques for recovery and purification of biosurfactants. In the traditional techniques, large volumes of organic solvents are usually used for increasing production cost and the overall environmental burden. In addition, traditional production and separation methods typically carried out in batch cultures reduce biosurfactant yields due to product inhibition and lower biosurfactants activity as a result of interaction with the organic solvents used. However, some in situ recovery methods that allow continuous separation of bioproducts from culture broth leading to an improvement in yield production and fermentation efficiency. For biosurfactants commercialization, enhancement of product capacity of the separation methods and the rate of product removal is critical. Recently, interest in the integration of separation methods with a production step as rapid and efficient techniques has been increasing. This review focuses on the technology gains and potentials for the most common methods used in in situ product removal: foam fractionation and ultrafiltration, especially used to recover and purify two well-known biosurfactants: glycolipids (rhamnolipids) and lipopeptides (surfactins).

BackgroundAlkaline thermostable lipase and biosurfactant producing bacteria are very interested at detergent applications, not only because of their eco-friendly characterize, but alsoproduction lipase and biosurfactant by using cheap materials. Ochrobactrum intermedium strain MZV101 was isolated as washing powder resistant, alkaline thermostable lipase and biosurfactant producing bacterium in order to use at detergent applications.Methods O. intermedium strain MZV101 produces was lipase and biosurfactant in the same media with pH 10 and temperature of 60 °C. Washing test and some detergent compatibility character of lipase enzyme and biosurfactant were assayed. The antimicrobial activity evaluated against various bacteria and fungi.ResultsLipase and biosurfactant produced by O. intermedium strain MZV101 exhibited high stability at pH 10–13 and temperature of 70–90 °C, biosurfactant exhibits good stability at pH 9–13 and thermostability in all range. Both lipase and biosurfactant were found to be stable in the presence of different metal ions, detergents and organic solvents. The lipase enzyme extracted using isopropanol with yield of 69.2% and biosurfactant with ethanol emulsification index value of 70.99% and yield of 9.32 (g/l). The single band protein after through from G-50 Sephadex column on SDS-PAGE was calculated to be 99.42 kDa. Biosurfactant O. intermedium strain MZV101 exhibited good antimicrobial activity against Gram-negative bacteria and against various bacterial pathogens. Based upon washing test biosurfactant and lipase O. intermedium strain MZV101considered being strong oil removal.ConclusionThe results of this study indicate that isolated lipase and biosurfactant with strong oil removal, antimicrobial activity and good stability could be useful for detergent applications.Graphical abstract

Pediococcus spp. were isolated from poultry rectum, faeces and food as good probiotic candidates in order to select strains to be used as probiotic in poultry feed. A total of 168 lactic acid bacteria were isolated and 51 isolates including 31 Lactobacillus spp. and 20 Pediococcus spp. were able to survive in low pH and bile salt concentration. The Pediococcus spp. were identified and their ability to form biofilm, adhesion to Caco-2 cells and antimicrobial activities against enteric pathogenic bacteria were determined. The results showed the presence of two strains, Pediococcus acidilactici P17 and P19 in rectal swab samples from 21-d old chickens with significant antibacterial activities against Salmonella enteritidis and Escherichia coli. The results suggest that only a few isolates of Pediococcus with potential probiotic activities are present in the poultry industry.

Halotolerant bacteria are regarded as effective oil-scavengers in the polluted saltern and seawater. In this regard, a halotolerant Planococcus was isolated from oilcontaminated area of Dezful north springs, Iran, due to its capacity in biosurfactant (BS) production. To facilitate hydrocarbons degradation, in the current study, the efficiency of BS production as function of growth rate of the halotolerant Planococcus was investigated in the vicinity of heavy crude oil by emulsification index (E24). Subsequently, the BS characterization was made by thin-layer chromatography (TLC), gas chromatography (GC) and infrared spectra analysis, and the stability was determined by E24 value measurement over a certain pH (5-9), temperature (20-100°C) and salt concentration (0-10 % w/v) ranges. The BS production was found to be growth-associated. Detection of a unique band on TLC and GC chromatogram showed the extensive refining capacity of the BS purification, using the medium supernatant under acetone alkaline precipitation followed by oil dissolution from the sediment by carbon tetrachloride. Accordingly, it was clarified that the BS ultimately accumulated outside the cells. The glycolipid quality of the BS was further determined by the routine chemical characterization on TLC and by IR spectra analysis. Moreover, there was no protein detected by lowery total protein assay. Finally, the optimal temperature, pH and NaCl concentration to reach highest E24 values (85.7, 77.0, and 79.0 %) were found at respective 40°C, pH = 9 and 0 % w/v. Our results revealed the practically potential of strain Dezful Isolate for BS large-scale production as environmentally friendly oil-eliminating agents.

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