Surface Properties of Bacteria from Different Wastewater Treatment Plants

Abstract

The surface properties of the individual members of degradative biocommunities isolated from different laboratory and natural populations were characterized. The bacterial strains isolated from a given origin and degrading a given substrate varied with respect to their hydrophobic and electrostatic properties (e.g. contact angle, adsorption to hexadecane, isoelectric point, adsorption of anionic or cationic dyes). However, despite their specific surface characteristics, in most cases the net charge properties of different bacterial strains (characterized by the zeta potential profiles of the bacteria in relation to the pH) were found to be related to the substrate the bacteria were able to degrade as well as to the consortium the bacteria were isolated from. For one group of specialized bacteria, only one or at most two characteristic zeta potential profiles were measured. Compared to the differences between different strains, the zeta potential profiles of individual strains were only slightly affected by either growth state or changes in the actual nutrient composition. Even if isolated strains were cultivated in standard nutrient broth for several months, only slight differences in the zeta potential profiles were measured. Only the isoelectric focusing experiments indicated that cultivation in a complex medium favoured a progressively decreased uniformity of surface charge properties. Thus, measurement of zeta potential profiles under standardized conditions may be a useful means to compare the surface structures of bacteria from different origins.

Alteration in cell surface properties of Burkholderia spp. during surfactant-aided biodegradation of petroleum hydrocarbons

“…Only a marginal variation in IEP was observed in the presence of the chemical surfactants, i.e., the IEP range was 2.3-2.6 for B. cepacia (ES1) and 2.0-2.7 for B. multivorans (NG1). Martienssen et al (2001) reported the IEP of several bacterial cultures isolated from wastewater treatment plants to be in the range of 3-3.8. Van der Wal et al (1997) reported the IEP of five Gram-positive bacterial cultures which were also in the above range, except Rhodococcus erythropolis A177, which demonstrated an IEP ≤2.0.…”

“…At 60 h (log growth phase), the zeta potential in the presence of varying doses of Triton X-100 was less electronegative compared to that at 36 (mid-log) and 168 h (stationary phase). The net charge on the cell surface is a result of interaction of functional groups present on the cell surface, and since presence/abundance of these groups is metabolically regulated (Martienssen et al 2001), some variation may be expected over the growth phase.…”

Effect of Glucopon 215 on cell surface properties of Pseudomonas stutzeri and diesel oil biodegradation

“…This charge on cell surface is a result of an interaction of functional groups present on microorganisms' cell surface. Furthermore, the presence or abundance of these groups is metabolically regulated (Marienssen et al, 2001). The presence of a surfactant in the system can lead to an alteration in cell surface functional groups.…”

Capillary isoelectric focusing of proteins and microorganisms in dynamically modified fused silica with UV detection

“…The microbes are different in their size, shape and in the composition of the outer membranes, which include the large number of lipids, proteins, etc. The isoelectric points, pI's, of microbes [3] are more appropriate parameters than the electrophoretic mobilities; pI's are practically independent from the measurement conditions [4,5]. Several papers were published showing the successful separation of microorganisms according to their pI by capillary isoelectric focusing (CIEF) [1,5,6].…”