Study investigated genetics behind biocontrol, biopreservative properties
COLLEGE STATION — About 1.3 billion tons of food are lost or wasted annually, representing nearly one-third of the global food mass for human consumption, some of which could be saved, said Dr. Joseph Sturino, lead researcher on a recently published study on the biopreservative strain of Pediococcus acidilactici, called D3.
The study, titled “Draft Genome Sequence of the Pediocin-Encoding Biopreservative and Biocontrol Strain Pediococcus acidilactici D3,” was published June 20 in Genome Announcements, GenomeA, an online, open-access journal of the American Society for Microbiology. It can be found at http://genomea.asm.org.
“As the world population is expected to grow by more than 2.3 billion people between 2009 and 2050, the reduction of food loss and waste is a critical benchmark to improve food security and environmental sustainability across the globe,” said Sturino, a faculty member in the nutrition and food science department of the Texas A&M University System’s College of Agriculture and Life Sciences. “Innovative technologies, including biopreservative and biocontrol cultures, are being developed to address these grand challenges.”
Sturino explained that biopreservative and biocontrol cultures are living microorganisms that, when applied in adequate amounts, extend the storage life and safety of beverages, foods or feeds without changing their “organoleptic” properties. Organoleptic properties are those characteristics experienced through the senses, such as taste, sight and smell.
“Pediococcus acidilactici D3 is a component of lactic acid bacteria-based biocontrol cultures that are generally recognized as safe for use in certain meat products,” he said. “To date, however, molecular evidence to confirm the involvement of specific genes in the culture’s antimicrobial function has been lacking.”
As a result, Sturino and other researchers from the Texas A&M University System and Dr. Eric Altermann, AgResearch Ltd., Palmerston North, New Zealand and the Riddet Institute, Massey University, also in Palmerston North, set out to generate a draft sequence of the genome so it could be examined.
“To this end, we cut the D3 genome into small fragments and then sequenced the fragments using an Illumina next-generation sequencer at the Texas AgriLife Genomics and Bioinformatics Center in College Station, Texas,” Struino explained. “Scott Schwartz, Richard Metz, and Charlie Johnson from the Texas AgriLife Genomics and Bioinformatics Center provided excellent technical support throughout the process.”
“Based on our analyses, 1,976 protein-coding genes were predicted,” Sturino explained. “A closer examination of these genes showed that D3 carries four genes associated with an antimicrobial peptide, pediocin. And the sequence is identical to that of another well-studied pediocin.”
He said pediocins are highly effective and useful biopreservatives due to their thermostability, ability to function within a wide pH range and proven activity against Gram-positive food spoilage and pathogenic bacteria, such as Listeria monocytogenes.
“This study provided a more definitive and empirical understanding of the genetics behind the biopreservative and biocontrol properties of P. acidilactici,” he said.
Sturino said Guardian Food Technologies of Overland Park, Kan. provided P. acidilactici D3 and funded the sequencing project, but had no role in the study design, data collection or analysis, or the production of the submitted manuscript.