GERBAM — Deuxième Colloque International de Bactériologie marine — CNRS, Brest, 1-5 octobre 1984
IFREMER, Actes de Colloques, 3, 1986, pp. 611-615
73
EFFECT OF XANTHAN ON THE GROWTH OF SULPHATE-REDUCING BACTERIA IN MARINE SEDIMENTS
N.S. BATTERSBY, D.J. STEWART and A.P. SHARMA
Department of Biological Sciences, Heriot-Watt University
Chambers street, EDINBURGH EH 1 1HX, (UK)
ABSTRACT - Chemical additives are used extensively in the off-shore oil industry. For secondary oil recovery,
the biopolymer xanthan has been recommended as a vicosifying agent but its use may provoke microbial
problems. The effect of adding xanthan to marine sediments on the growth and metabolic activity of sulphatereducing bacteria (SRB) was studied. In all instances, its addition resulted in an increase in SRB numbers of up
to 250-fold. This was accompanied by a marked increase in the electron transport activity of the sediments when
these were incubated under either aerobic or anaerobic conditions. The products formed as a result of the
biodegradation of the polymer by indigenous heterotrophic bacteria in these sediments appear to have acted as
suitable substrates for SRB growth.
Key words: xanthan, secondary oil recovery, sulphate-reducing bacteria, ETS activity.
RÉSUMÉ - Les additifs chimiques sont utilisés de façon considérable dans l’industrie pétrolière off shore. Pour la
récupération assistée du pétrole, le biopolymère xanthane a été recommandé comme agent de viscosité mais son
utilisation peut provoquer des problèmes microbiens. L’effet de l’addition du xanthane à des sédiments marins
est étudié sur la croissance et l’activité métabolique de bactéries sulfato-réductrices (SRB). Dans tous les cas,
cette addition entraîne une augmentation du nombre de bactéries sulfato-réductrices qui peut atteindre un
facteur de 250. Ceci s’accompagne d’un développement important de l’activité de transport des électrons dans le
sédiment, l’incubation ayant lieu en milieu aérobie ou anaérobie. Le produit formé lors de la biodégradation du
polymère par les bactéries hétérotrophes du sédiment semble être utilisé comme substrat disponible favorisant le
développement des bactéries sulfato-réductrices.
Mots clés: xanthane, récupération assistée, bactéries sulfato-réductrices, activité de transport des électrons.
INTRODUCTION
Sulphate-reducing bacteria (SRB) create many problems for the oil industry. Their
activities are perhaps most difficult to control in the sulphate-rich environment of the
North Sea. The group respire sulphate to sulphide during the anaerobic oxidation of a
somewhat restricted range of organic substrates such as simple organic acids and alcohols. Some strains can, however, utilize higher fatty acids (up to C-14) and aromatic
compounds as carbon sources and electron donors (Pfennig et al., 1981). SRB appear
incapable of growth on high molecular weight compounds such as the biopolymer
cellulose. Although they are obligately anaerobic organisms, SRB can survive in oxic
North Sea waters in numbers of ca 0 to 90/ml (Hardy, 1981). However, anaerobic
conditions and the presence of suitable electron donors can result in rapid increases in this
SRB population to ca 10 6 /ml (Wilkinson, 1982).
611
IFREMER, Actes de Colloques, 3, 1986, pp. 611-615
73
EFFECT OF XANTHAN ON THE GROWTH OF SULPHATE-REDUCING BACTERIA IN MARINE SEDIMENTS
N.S. BATTERSBY, D.J. STEWART and A.P. SHARMA
Department of Biological Sciences, Heriot-Watt University
Chambers street, EDINBURGH EH 1 1HX, (UK)
ABSTRACT - Chemical additives are used extensively in the off-shore oil industry. For secondary oil recovery,
the biopolymer xanthan has been recommended as a vicosifying agent but its use may provoke microbial
problems. The effect of adding xanthan to marine sediments on the growth and metabolic activity of sulphatereducing bacteria (SRB) was studied. In all instances, its addition resulted in an increase in SRB numbers of up
to 250-fold. This was accompanied by a marked increase in the electron transport activity of the sediments when
these were incubated under either aerobic or anaerobic conditions. The products formed as a result of the
biodegradation of the polymer by indigenous heterotrophic bacteria in these sediments appear to have acted as
suitable substrates for SRB growth.
Key words: xanthan, secondary oil recovery, sulphate-reducing bacteria, ETS activity.
RÉSUMÉ - Les additifs chimiques sont utilisés de façon considérable dans l’industrie pétrolière off shore. Pour la
récupération assistée du pétrole, le biopolymère xanthane a été recommandé comme agent de viscosité mais son
utilisation peut provoquer des problèmes microbiens. L’effet de l’addition du xanthane à des sédiments marins
est étudié sur la croissance et l’activité métabolique de bactéries sulfato-réductrices (SRB). Dans tous les cas,
cette addition entraîne une augmentation du nombre de bactéries sulfato-réductrices qui peut atteindre un
facteur de 250. Ceci s’accompagne d’un développement important de l’activité de transport des électrons dans le
sédiment, l’incubation ayant lieu en milieu aérobie ou anaérobie. Le produit formé lors de la biodégradation du
polymère par les bactéries hétérotrophes du sédiment semble être utilisé comme substrat disponible favorisant le
développement des bactéries sulfato-réductrices.
Mots clés: xanthane, récupération assistée, bactéries sulfato-réductrices, activité de transport des électrons.
INTRODUCTION
Sulphate-reducing bacteria (SRB) create many problems for the oil industry. Their
activities are perhaps most difficult to control in the sulphate-rich environment of the
North Sea. The group respire sulphate to sulphide during the anaerobic oxidation of a
somewhat restricted range of organic substrates such as simple organic acids and alcohols. Some strains can, however, utilize higher fatty acids (up to C-14) and aromatic
compounds as carbon sources and electron donors (Pfennig et al., 1981). SRB appear
incapable of growth on high molecular weight compounds such as the biopolymer
cellulose. Although they are obligately anaerobic organisms, SRB can survive in oxic
North Sea waters in numbers of ca 0 to 90/ml (Hardy, 1981). However, anaerobic
conditions and the presence of suitable electron donors can result in rapid increases in this
SRB population to ca 10 6 /ml (Wilkinson, 1982).
611