Ascorbic Acid Enhances Oxidative Stress Tolerance and Biological Control Efficacy of Pichia caribbica against Postharvest Blue Mold Decay of Apples

Abstract

The effect of ascorbic acid (VC) on improving oxidative stress tolerance of Pichia caribbica and biocontrol efficacy against blue mold caused by Penicillium expansum on apples was investigated. P. caribbica showed susceptibility to the oxidative stress in vitro test, and 250 μg/mL VC treatment improved its oxidative stress tolerance. The higher viability exhibited by VC-treated yeast was associated with a lower intracellular ROS level. The activities of antioxidant enzymes of P. caribbica were improved by VC treatment, including catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPX). Additionally, VC-treated yeast exhibited greater biocontrol activity against P. expansum and faster growth when stored at 25 and 4 °C, respectively, compared to the performance of the non-VC-treated yeast. In response to the VC treatment under oxidative stress, several differentially expressed proteins were identified in P. caribbica, and most of the poteins were confirmed to be related to basic metabolism. Therefore, the application of ascorbic acid is a useful approach to improve oxidative stress tolerance of P. caribbica and its biocontrol efficacy on apples.

Effects of Sporidiobolus pararoseus Y16 on Postharvest Blue Mold Decay and the Defense Response of Apples

“…The method to evaluate the population studies of S. pararoseus Y16 in apple wounds was according to [15] with some modifications. Each wound on apple was inoculated with 30 L of S. pararoseus Y16 (10 8 cells/mL), and then apples were stored at 20 ∘ C and 4 ∘ C, respectively.…”

“…The tissue of apple wound was removed with a sterile knife and macerated in 50 mL of sterile 0.85% sodium chloride solution and quartz sand in a mortar. The amount of S. pararoseus Y16 was recovered from the wounds after incubation at 20 ∘ C for 0 (1 h after treatment), 1, 2, 3, 4, 5, 6, 7, and 8 days and at 4 ∘ C for 0 (1 h after treatment), 3,6,9,12,15,18,21, and 23 days, respectively. 10-fold serial dilutions were made and 100 L of each dilution was spread by coated rod on the NYDA plates, stored in incubator at 28 ∘ C for 48 hours, and then expressed as the log 10 CFU per wound.…”

Responses of Yeast Biocontrol Agents to Environmental Stress

“…Glucose provided a highly significant (over 90%) protective effect on cell viability in Pichia guilliermondii exposed to 45°C (36). Ascorbic acid, as an antioxidant, has been applied alone (32) or in combination with various sugars (33) to enhance oxidative stress tolerance and biocontrol efficacy. Glycine betaine (N,N,N-trimethyl glycine), a compatible solute, not only acts as an osmoprotectant but also induces an antioxidant response in biocontrol yeasts at either the transcriptional level (Candida oleophila [31]) or the enzymatic level (Cystofilobasidium infirmominiatum [30]).…”

“…In this regard, several methods, including physiological manipulation (23,24), stress adaptation (25,26), cross-protection (27,28), and the use of exogenous antistress substances/protectants such as calcium (29), glycine betaine (30,31), ascorbic acid (32,33), sugars (33)(34)(35)(36), and polyols (37), have been employed to enhance stress tolerance and improve biocontrol efficacy. The purpose of the current review is to provide an overview of research on the role of environmental stresses which affect the viability and performance of antagonistic yeasts.…”

Combining UV-C treatment with biocontrol yeast to control postharvest decay of melon

“…In addition to UV-C treatment, biological control utilizing antagonistic yeasts has been examined as a potential alternative to chemical fungicides in managing postharvest decay (Wilson and Wisniewski 1989;Wisniewski and Wilson 1992;Droby et al 2009;Liu et al 2013). Many yeasts in the genus Pichia, including Pichia membranaefaciens, Pichia anomala, Pichia guilliermondii, and Pichia caribbica, have been reported as effective biocontrol agents for the control of postharvest diseases of apple, citrus, banana, and kiwifruit (Wisniewski et al 1991;Lassois et al 2008;Lahlali et al 2014;Li et al 2014;.…”