Postharvest Biology and Technology 92 (2014) 9–15
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Effect of chitin on the antagonistic activity of Rho paludig pp
Huangpi g, Ti
Department of titute
Hangzhou 3100 a r t i c l
Received 17 Se
Accepted 8 Jan
Postharvest bi fect o he ca ocon ed fro nutri esist was in ap num t cells etho the active oxygen metabolism of R. paludigenum might be closely related to the biocontrol activity of the yeast. © 2014 Elsevier B.V. All rights reserved. 1. Introdu
Blue mo is one of t considerabl wide (Yu e remains the harvested f friendly alte of the pote ronment by 2009).
Postharv has emerge recent year that the ma
Tallman iso cacy in inh black rot of ∗ Correspon
Tel.: +86 571 8 ∗∗ Correspon
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E-mail add 0925-5214/$ – http://dx.doi.oction ld of apple fruit caused by Penicillium expansum link he major postharvest diseases, which accounts for e postharvest economic losses of apple fruit worldt al., 2012). Although the use of synthetic fungicides primary strategy for controlling fungal pathogens in ruit, there is an increased need to seek safer and ecornatives for inhibition of postharvest diseases because ntial harmful effects on human health and the envifungicide residues (Droby et al., 2009; Sharma et al., est biological control employing antagonistic yeasts d as a promising alternative to synthetic fungicides in s (Droby et al., 2009). Our previous studies indicated rine yeast strain of Rhodosporidium paludigenum Fell & lated from the East China Sea has great biocontrol effiibiting various postharvest diseases of fruit, including cherry tomato and Chinese winter jujube caused by ding author at: 866 Yuhangtang Road, Hangzhou 310058, PR China. 8982398; fax: +86 571 88982191. ding author at: 866 Yuhangtang Road, Hangzhou 310058, PR China. 8982861; fax: +86 571 88982191. resses: firstname.lastname@example.org (T. Yu), email@example.com (X. Zheng).
Alternaria alternata (Wang et al., 2008, 2009), gray mold of cherry tomato caused by Botrytis cinerea (Wang et al., 2010c), and sour rot of citrus caused by Geotrichum citri-aurantii (Liu et al., 2010b).
Moreover, it was found that the biocontrol efficacy and stress tolerance of R. paludigenum could be improved by salt-adaptation (Wang et al., 2010b) and acid-adaptation treatments (Wang et al., 2013), while the disease resistance against Penicillium digitatum and Penicillium italicum in citrus fruit was strongly induced by R. paludigenum treatment, when applied pre- or postharvest (Lu et al., 2013a,b). However, like other antagonistic yeasts, R. paludigenum, when used alone, could not control the postharvest diseases as effectively as synthetic fungicides, hence several strategies have been proposed to improve the efficacy of antagonistic yeasts. For instance, its biocontrol efficacy was found to be enhanced in combination with calcium chloride (Wang et al., 2010a), food additive carboxymethylcellulose sodium (Wang et al., 2011) and sodium bicarbonate (Zhu et al., 2013).
This study aims to (1) determine the influence of different concentrations of chitin in the media on the efficacy of R. paludigenum in controlling postharvest blue mold decay in apple fruit; (2) measure the ability of R. paludigenum to induce disease resistance in apple fruit; (3) evaluate the effect of chitin on population growth of R. paludigenum in wounds in apple fruit; (4) investigate the effect of R. paludigenum on enzyme activities of apples; and (5) analyze the influence of chitin on antioxidant enzyme activities and malondialdehyde (MDA) content of R. paludigenum. see front matter © 2014 Elsevier B.V. All rights reserved. rg/10.1016/j.postharvbio.2014.01.009enum against Penicillium expansum in a ng Lu, Laifeng Lu, Lizhen Zeng, Da Fu, Hualing Xian
Food Science and Nutrition, Zhejiang Key Laboratory for Agro-Food Processing, Fuli Ins 58, PR China e i n f o ptember 2013 uary 2014 paludigenum ansum ological control a b s t r a c t
This study aimed to investigate the ef genum against Penicillium expansum, t involved. Our results showed that bi greatly enhanced when it was harvest compared with that harvested from genum produced in NYCB to induce r
The enhanced disease control efficacy superoxide dismutase (SOD) activities catalase (CAT) activities of R. paludige hyde (MDA) accumulation in the yeas normal media might be an effective mdosporidium le fruit ng Yu ∗, Xiaodong Zheng ∗∗ of Food Science, Zhejiang University, f chitin on the antagonistic activity of Rhodosporidium paludiuse of blue mold in apple fruit, and the possible mechanisms trol efficacy and population growth of R. paludigenum were m nutrient yeast dextrose with added chitin (NYCB) medium ent yeast dextrose (NYDB) medium. The ability of R. paludiance to blue mold in apple fruit was significantly enhanced. correlated with higher levels of polyphenoloxidase (PPO) and ple fruit treated with R. paludigenum. Moreover, the SOD and were stimulated by cultivating in NYCB, while malondialdewas suppressed. These results indicated that adding chitin to d to improve the antagonistic activity of R. paludigenum and 10 H. Lu et al. / Postharvest Biology and Technology 92 (2014) 9–15 2. Materials and methods 2.1. Yeast
The mar paper was fied by CAB et al., 2008) yeast dextr extract, 10 g bated at 28 was added i cultivated o of 2 mL of s chitin powd tions (deno 200 rpm for at 4000 rpm in order to trations we required wi 2.2. Pathog
The path decayed ap agar (PDA) of glucose a day-old spo and suspen the pathoge required wi 2.3. Fruit
Apple (M the comme were used i in 0.1% (v/v twice and t 2.4. Efficacy containing d mold of app
Apple fr the equato was treated cell suspen paludigenum