Antimicrobial activity of grape seed extract on Alicyclobacillus acidoterrestris DSM 3922 vegetative cells and spores in apple juice

Abstract

Chemical compounds studied in this article: Grape seed extract (proanthocyanidins) (PubChem CID: 108065) gallic acid (PubChem CID: 370) disodium carbonate (PubChem CID: 10340) sodium acetate trihydrate (PubChem CID: 23665405) 2,4,6-tripyridyl-s-triazine (PubChem CID: 77258) iron chloride (PubChem CID: 24380) a b s t r a c tThe present study evaluated the antimicrobial activity of grape seed extract (GSE) against Alicyclobacillus acidoterrestris vegetative cells and spores in apple juice (pH 3.82, Brix 11.3) during storage at 37 C. After 336 h, reductions in the cell numbers were 3.14, 3.55, 3.8, 4.1, and 4.63 log CFU/mL in the apple juice with 0.23, 0.45, 0.9, 1.8, and 3.6% of GSE, respectively. The Weibull was found to be the best fitted model for cell inactivation kinetics (R 2 > 0.988). Moreover, the spores produced on different sporulation media (potato dextrose agar, malt extract agar, Bacillus acidoterrestris agar, and Bacillus acidocaldarius agar) were treated with GSE (0e1.9%, v/v). While control spores in apple juice without GSE increased by 2.2e2.6 log CFU/mL within the first 48 h, 0.9% and 1.8% of GSE inhibited the growth from all spore suspensions. Finally, scanning electron microscopy (SEM) indicated that the main target of the GSE may be the membrane of A. acidoterrestris cells leading to leakage of cellular constituents and may prevent the development of spores into vegetative cells. This study highlights the potential use of the by-products of the fruit juice/ beverage industry as natural antimicrobials to inhibit the growth of A. acidoterrestris.

Evaluation of bioactivity of pomegranate fruit extract against Alicyclobacillus acidoterrestris DSM 3922 vegetative cells and spores in apple juice

“…4). In the related literature, the addition of grape seed extract into the apple juice was found to inhibit the endospore germination of A. acidoterrestris (Molva & Baysal, 2015). In the previous study, the antimicrobial activity of grape extract was found sporulation media dependent and the spores produced on mineral containing media such as BATA and BAA were more sensitive to treatments.…”

“…acidoterrestris DSM 3922 was kindly provided by Karl Poralla (Deutsche Sammlung von Mikroorganismen und Zellkulturen's collection, Braunschweig, Germany). For spore preparation, aliquots of 100 mL 4 hegrown culture in Bacillus acidoterrestris broth (BATB, D€ ohler, Germany) were spread plated onto Bacillus acidoterrestris agar (BATA, Merck), Bacillus acidocaldarius agar (BAA) (Darland & Brock, 1971), potato dextrose agar (PDA, BD Difco) and malt extract agar (MEA, Oxoid) (Molva & Baysal, 2015). The plates were incubated at 43 C until 85e90% of the sporulation was achieved.…”

“…The antimicrobial activity of PE on both A. acidoterrestris cells and spores in apple juice was determined according to Molva and Baysal (2015). Briefly, overnight cultures of A. acidoterrestris cells were standardized to a bacterial density of McFarland 2.0 (10 7 CFU/ mL) in 10 mL Maximum Recovery Diluent (MRD, Oxoid) using a Densitometer (Dene1, HVD Life Sciences, Austria).…”

“…The controls and treated samples were prepared according to a previously published method (Molva & Baysal, 2015). The samples were goldecoated at a vacuum of 0.09 mbar, for 90 s, at 15 kV, in argon gas at a power of 15 mA, followed by analysis using a scanning electron microscope (Phillips XLe30S FEG).…”

“…In the literature, the investigation of the antimicrobial activity of plant extracts against A. acidoterrestris is very limited. To the best of our knowledge, the extracts of Piperaceae (Ruiz et al, 2013), Eucalyptus leaf (Takahashi, Kokubo, & Sakaino, 2004), and grape seed (Molva & Baysal, 2015) have been tested to inhibit the growth of A. acidoterrestris. It is of interest to discover natural plant extracts that have the potential to be used against A. acidoterrestris.…”