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While it is known that dif­fer­ent microor­gan­isms thrive in extra vir­gin olive oil, many went unde­tected until now and some may lead to improved olive oil pro­duc­tion prac­tices and new kinds of prod­ucts.

New research from a team of micro­bi­ol­o­gists at the University of Sassari, in Sardinia, described extra vir­gin olive oil as a rich basin of bac­te­r­ial bio­di­ver­sity. Among the poten­tial uses for these microor­gan­isms are in the cre­ation of pro­bi­otic-enriched foods and agri­cul­tural biotech­nol­ogy prod­ucts.

“We observed sev­eral species of microor­gan­isms in extra vir­gin olive oil and found that their qual­ity and quan­tity varies from vari­ety to vari­ety,” Serevino Zara, one of the nine researchers involved in the study, told Olive Oil Times.

The researchers exam­ined bac­te­ria in oil pro­duced in a con­trolled envi­ron­ment from 15 dif­fer­ent olive trees vari­eties, among them Frantoio, Coratina, Bosana and Semidana.

While pre­vi­ous research stud­ied the pres­ence of bac­te­ria, their con­cen­tra­tion was often below the lim­its of detec­tion by stan­dard cul­ture meth­ods. Through adopt­ing new tech­niques, sci­en­tists are now able to eval­u­ate these bac­te­ria con­cen­tra­tions.

“As expected, we found fewer dif­fer­ent species of bac­te­ria in olive oils that are rich in polyphe­nols because of their antibac­te­r­ial prop­er­ties,” Zara said. ​“Extra vir­gin olive oil is an extreme envi­ron­ment, the bac­te­ria that live there could eas­ily sur­vive else­where, which means that they could be adopted in sev­eral fields of appli­ca­tion.”

He added that the oil pro­duc­tion process impacts the quan­tity and vari­ety of bac­te­ria in the final prod­uct.

“We first looked for the microor­gan­isms in the olives, then in the fol­low­ing steps of the trans­for­ma­tion process and after that in the pro­duced olive oil,” Zara explained.

The quan­tity of bac­te­ria detected decreased after each step in the process, but sev­eral types of microor­gan­isms still thrived in the final prod­uct.

Among the fore­see­able appli­ca­tions for the research is the use of the pro­bi­otics found in the sam­ples. This hints at the pos­si­bil­ity of pro­duc­ing a new range of prod­ucts, includ­ing pro­bi­otic extra vir­gin olive oil, which could appeal to those who usu­ally turn to pro­bi­otic dairy prod­ucts.

“Other microor­gan­isms found in extra vir­gin olive oil could trig­ger new more effi­cient biotech­nolo­gies for the envi­ron­ment restora­tion oper­a­tions, both on land and sea, because of their abil­ity to digest indus­trial oils and trans­form them into com­pounds that can be absorbed by the envi­ron­ment with­out fur­ther dam­age,” Zara said.

Researchers also found some evi­dence of antibi­otic resis­tance in some bac­te­ria, a nat­ural occur­rence that was inves­ti­gated because of the rel­e­vance of the mat­ter on pub­lic health.

Bacterial con­cen­tra­tion in extra vir­gin olive oil des­tined for con­sump­tion is so low that it does not rep­re­sent any kind of threat to human health, but the spe­cific char­ac­ter­is­tics of the microor­gan­isms in those low con­cen­tra­tions could be used to develop new biotech­nolo­gies.

“Several microor­gan­isms could pro­duc­tively be used as plant growth induc­ers, for instance, and in such a case, it is quite rel­e­vant to under­stand how they could affect the biotech­nol­ogy prod­uct and the plants them­selves,” Zara con­cluded, hint­ing that fur­ther research on extra vir­gin olive oil bac­te­ria was needed.

• Journal of Microorganisms