• Korean Journal of Environmental Agriculture
• /
• v.37 no.3
• /
• pp.221-228
• /
• 2018

BACKGROUND: Spoilage fungi can reduce the shelf life of fresh fruits and cause economic losses by lowering quality. Especially, mulberry fruits have high sensitivity to fungal attack due to their high water content (> 70%) and soft texture. In addition, the surface of these fruits is prone to damage during harvesting and postharvest handling. However, any study on postharvest spoilage fungi in mulberry fruit has not been reported in Korea. This study aimed to examine the spoilage fungi occurring in mulberry fruits during storage after harvest. METHODS AND RESULTS: In this study, we isolated postharvest spoilage fungi from mulberry fruits stored in refrigerator (fresh fruits) and deep-freezer (frozen fruits) and identified them. In the phylogenetic analysis based on comparisons of the ITS rDNA sequences, the 18 spoilage fungi isolated from mulberry fruits and the 25 reference sequences were largely divided into seven groups that were subsequently verified by high bootstrap analysis of 73 to 100. Alternaria spp. including A. alternate and A. tenuissima, were the most frequently isolated fungi among the spoilage isolates: its occurrence was the highest among the 18 isolates (38.9%). CONCLUSION: The findings of this study will be helpful for increasing the shelf life of mulberry fruits through the application of appropriate control measures against infection by spoilage fungi during storage.

• Journal of Microbiology and Biotechnology
• /
• v.32 no.8
• /
• pp.989-1002
• /
• 2022

Cephalopods, in particular octopus (Octopus vulgaris), have the ability to alter their appearance or body pattern by showing a wide range of camouflage by virtue of their chromatophores, which contain nanostructured granules of ommochrome pigments. Recently, the antioxidant and antimicrobial activities of ommochromes have become of great interest; therefore, in this study, the pH-dependent redox effect of the extraction solvent on the antioxidant potential and the structural characterization of the pigments were evaluated. Cell viability was determined by the microdilution method in broth by turbidity, MTT, resazurin, as well as fluorescence microscopy kit assays. A Live/Dead Double Staining Kit and an ROS Kit were used to elucidate the possible inhibitory mechanisms of ommochromes against bacterial and fungal strains. The results obtained revealed that the redox state alters the color changes of the ommochromes and is dependent on the pH in the extraction solvent. Natural phenoxazinone (ommochromes) is moderately toxic to the pathogens Staphylococcus aureus, Bacillus subtilis, Salmonella Typhimurium and Candida albicans, while the species Pseudomonas aeruginosa and Pseudomonas fluorescens, and the filamentous fungi Aspergillus parasiticus, Alternaria spp. and Fusarium verticillioides, were tolerant to these pigments. UV/visible spectral scanning and Fourier- transform infrared spectroscopy (FTIR) suggest the presence of reduced ommatin in methanol/ HCl extract with high intrinsic fluorescence.

• Research in Plant Disease
• /
• v.9 no.4
• /
• pp.229-236
• /
• 2003

The 1080 epiphytic bacteria obtained from 370 samples of pome and stone fruits including apple, pear, peach, grape, apricot and Chinese quince were screened for antagonistic activity against postharvest pathogens, Penicillium expansum, Alternaria alternata and Botrytis cinerea. Among tested antagonistic bacteria, eight bacterial isolates inhibited mycelial growth of the postharvest pathogens and were identified as Bacillus amyloliquefaciens (three strains), B. megaterium, B. subtilis var. gladioli, B. licheniformis, B. pumilus and Serratia marcescens based on biochemical characteristics and utility of carbon and nitrogen compounds (Biolog system). Eight carbohydrates were evaluated for their effect on mycelial growth and germination of the postharvest pathogen, P. expansum to select nutrients for enhancing bio-control efficacy. The growth of four selected antagonists, B. amyloliquefaciens P43-2, B. amyloliquefaciens A71-2, B. licheniformis P94-1, and S. marcescens P76-9 were also tested. As a result, 1% glucose (w/v) strongly stimulated growth of the antagonists, suppressed mycelial growth of the postharvest pathogen, and had a little comparatively stimulatory effect on germination of the the postharvest pathogen. It was confirmed that the addition of 1% glucose (w/v) greatly enhanced biocontrol effect of B. amyloliquefaciens P43-2, B. licheniformis P94-1, and S. marcescens P76-9. Application of B. amyloliquefaciens P43-2, B. licheniformis P94-1, and S. marcescens P76-9 with the addition of 1% glucose (w/v) increased the control efficacy up to 48%, 46%, 14% compared with those of the antagonists without glucose, respectively. When the antagonists were applied to control postharvest disease caused by P. expansum in apple wounds, the population of B. amyloliquefaciens P43-2 and B. licheniformis P94-1 increased until 4 days after inoculation (DAI) of the antagonists and then decreased from 10 DAI. Meanwhile the population of S. marcescens P76-9 decreased at early stage (4 DAI), but increased from 7 DAI, and finally maintained constantly until 10 DAI in apple wounds.

• Horticultural Science & Technology
• /
• v.34 no.4
• /
• pp.655-661
• /
• 2016

To develop scab-resistant pear (Pyrus spp.) varieties with fruits that are as crisp and juicy as Asian pears, a cross was made between 'Whangkeumbae' and 'Bartlett' varieties (P. pyrifolia ${\times}$ P. communis) at the Pear Research Institute of the National Institute of Horticultural & Herbal Science, Rural Development Administration, in 1994. Among the 285 seedlings, 'Greensis' was first selected in 2006 for its good eating quality and named in 2012 after regional adaptation tests in nine regions and ten experimental plots from 2007 to 2012. The tree showed a vigorous growth habit and semi-spreading characteristics, like 'Whangkeumbae'. The optimum fruit harvest date was also around Sept. 26 and fruit was round in shape and green in skin color at maturity. Average fruit weight was 470g, and the soluble solids content was $12.4^{\circ}Brix$. The flesh was very crisp and juicy, and had good eating quality. Its' leaf size was similar with 'Bartlett' and smaller than 'Whangkeumbae'. The average of full bloom date of 'Greensis' was determined as Apr. 26, which was six days later than 'Whangkeumbae' and similar with 'Bartlett'. S genotypes of 'Greensis' were identified as $S_4S_e$ by S-allele PCR product sequencing analysis. It seems that the $S_4$ allele was inherited from 'Whangkeumbae' and the Se allele from 'Bartlett'. 'Greensis' displayed strong resistance to scab disease caused by Venturia nashicola, similar to European pear cultivars like 'Beurre Hardy' and, 'Conference'. 'Greensis' was also highly resistant to black leaf spot (Alternaria kikuchiana) in the field