Microbial surfactant activities from a petrochemical landfarm in a humid tropical region of Brazil

Abstract

The goal of this study was to assess the presence and surfactant potential of naturally occurring microbes from a tropical soil with petrochemical contamination. Microorganisms in a soil sample from a Brazilian landfarm were isolated and grown on petroleum as the sole carbon source. Of 60 isolates screened for petroleum-based growth, 7 demonstrated surfactant activities by the drop-collapse methodology over various types of oils. From their growth profiles in liquid culture during 132 h, all had their first detection of surfactant activity after 96 h. Little is currently known about biosurfactant-producing microorganisms in tropical environments contaminated by hydrophobic compounds, and the search for them is essential for bioremediation and for oil recovery enhanced by microbes. Our results indicate that different petroleum-grown microorganisms showing surfactant activity can be recovered from landfarm soil in a tropical environment.

Bioprospection of bacteria and yeasts from Atlantic Rainforest soil capable of growing in crude-glycerol residues

“…The biotechnological use of microorganisms capable of biodegrading/bioconverting this residue has been the major approach proposed for handling this issue in an economic and environment-friendly manner (Pagliaro et al, 2007;Dobson et al, 2012). The identification of new microbe strains with advantageous features in metabolizing crude glycerol is a requirement, and the tendency in studies of this nature is to seek novel isolates exactly in those environments enriched with the same target substrate (e.g., Maciel et al, 2007;Franciscon et al, 2009). In the present work, we sought an alternative approach for the identification and isolation of microbial activity for consumption of crude glycerol, which was based upon an expectedly large functional biodiversity of soils from the Atlantic Rainforest.…”

“…New crude glycerol-degrading isolates can be used either alone or making up microbial consortia, which are showing to be very promising for this purpose (Gallego et al, 2007;Varrone et al, 2012). Not unexpectedly, the tendency in screening studies of this nature is to seek novel isolates exactly in those environments enriched with the same target substrate (e.g., Maciel et al, 2007;Franciscon et al, 2009), due to the higher possibility of finding microorganisms already adapted to these human-generated ecological niches. Nevertheless, other sources of diverse microbes should not be neglected, since glycerol is an abundant carbon source in nature (it is a structural component of many lipids), and so, likely prone to be metabolized by a great variety of microorganisms.…”

“…From the point of view of biotechnology, bacteria and yeasts are important groups because their representatives in terrestrial microbiota are recognized by the high species diversity, adaptive plasticity, and metabolic versatility, which allow their employment in numerous biodegradation processes (e.g., Maciel et al, 2007;Milić et al, 2009;Franciscon et al, 2009). The microbial biodiversity of soils from the Atlantic Rainforest is expectedly very large, due to a higher diversity of plants (Myers et al, 2000;Arnold et al, 2002) and to a much lower anthropic disturbance of this environment (Hanada et al, 2010).…”

Petroleum Hydrocarbon Spills in the Environment and Abundance of Microbial Community Capable of Biosurfactant Production

“…Species from these genera are reported as efficient biosurfactant producers [33][34][35][36][37][38]. The community in sample ENGB was dominated by members Germany).…”

Microbial Outlook for the Bioremediation of Crude Oil Contaminated Environments

“…In the first case, biosurfactants production begins simultaneously with microbial growth when the substrate is used. In contrast, production under limited growth conditions occurs only during substrate scarcity (Desai & Banat, 1997;Maciel et al, 2007;). Figure 4 shows different stages of bacterial growth and the corresponding kinetics for biosurfactant production.…”