K.R.N. Reddy

Publications (60) View all

• Source

  Available from: Carlos A F Oliveira

  Dataset: Article

  K. R. N. Reddy, H. K. Abbas, C. A. Abel, W. T. Shier, C. A. F. Oliveira, C. R. Raghavender
• Article: Potential of two Metschnikowia pulcherrima (yeast) strains for in vitro biodegradation of patulin.

  K R N Reddy, D Spadaro, M L Gullino, A Garibaldi
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  ABSTRACT: Patulin contamination of apple and other fruit-based foods and beverages is an important food safety issue, as consumption of these commodities throughout the world is great. Studies are therefore necessary to reduce patulin levels to acceptable limits or undetectable levels to minimize toxicity. This study was undertaken to investigate the efficacy of two Metschnikowia pulcherrima strains (MACH1 and GS9) on biodegradation of patulin under in vitro conditions. These yeast strains were tested for their abilities to degrade patulin in liquid medium amended with 5, 7.5, 10, and 15 μg/ml patulin and a yeast cell concentration of 1 × 10(8) cells per ml at 25°C. Of the two strains tested, MACH1 completely (100%) reduced patulin levels within 48 h, and GS9 within 72 h, at all concentrations of patulin. MACH1 effectively degraded the patulin within 24 h by 83 to 87.4%, and GS9 by 73 to 75.6% at 48 h, regardless of concentration. Patulin was not detected in yeast cell walls. This indicates that yeast cell walls did not absorb patulin, and that they completely degraded the toxin. Patulin had no influence on yeast cell concentration during growth. Therefore, these yeast strains could potentially be used for the reduction of patulin in naturally contaminated fruit juices. To our knowledge, this is the first report regarding the potential of M. pulcherrima strains for patulin biodegradation.
  Journal of food protection 01/2011; 74(1):154-6. · 1.94 Impact Factor
• Article: Potential of ochratoxin a production by Aspergillus carbonarius strains isolated from grapes at different ecological factors

  S Patharajan, V Karthikeyan, K R N Reddy, D Spadaro
  Archives of Phytopathology and Plant Protection 01/2011; 44(18):1802-1814.
• Article: Potential of patulin production by Penicillium expansum strains on various fruits.

  K R N Reddy, Davide Spadaro, Alessia Lore, M L Gullino, Angelo Garibaldi
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  ABSTRACT: In this study, we investigated the pathogenicity and patulin production by ten strains of Penicillium expansum on various fruits (apples, apricots, kiwis, plums and peaches) at two (4°C and 25°C) different temperature regimes. All strains caused the infectious rots on all fruits at 4 and 25°C except one strain (PEX 09) at 4°C. Two strains (PEX 20 and PEX 12) out of ten produced the highest amounts of patulin on all fruits tested. The patulin production by P. expansum is high at 25°C compared to 4°C. All strains of P. expansum accumulated patulin ranging from 100-13,200 μg/kg and nine strains ranging from 100-12,100 μg/kg in all fruits at 25°C and 4°C, respectively. Among ten strains of P. expansum, strain PEX 20 produced the greatest amount of patulin on apricots (13,200 μg/kg of rotten fruit) and on apples (12,500 μg/kg) at 25°C after 9 days of incubation. At 4°C, this strain produced 12,100, 12,000, 2,100 and 1,200 μg/kg of patulin on apricots, apples, plums and peaches, respectively, after 45 days of incubation. Strain PEX 12 produced the highest amount of patulin on kiwis (10,700 μg/kg) at 25°C and 10,300 μg/kg at 4°C. Patulin production by P. expansum on peaches and plums at both temperatures were lower than other fruits. The results of this study showed that careful removal of rotten fruits is essential to produce patulin-free fruit juice, since high patulin levels in apricots, apples and kiwis could result in a level greater than 50 μg/kg of this mycotoxin in finished fruit juices, when one contaminated fruit occurs in 264, 250 and 214 fruits, respectively. So, the fruit processors should take care in not using rotten fruits for juice production to avoid the patulin problem worldwide, since this study proved that most important fruits being used for juice production and direct human consumption are susceptible to P. expansum and subsequent patulin production even at low temperatures. This is the first comprehensive report regarding patulin production by different strains of P. expansum on various fruits from Italy at different temperature regimes.
  Mycotoxin Research 11/2010; 26(4):257-65.
• Source

  Available from: ajol.info

  Article: Aflatoxin B 1 producing potential of Aspergillus flavus strains isolated from stored rice grains

  K R N Reddy, P Saritha, C S Reddy, K Muralidharan
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  ABSTRACT: Aflatoxin B 1 (AFB1) producing potential of different strains of Aspergillus flavus, isolated from 1,200 stored rice grains collected from 43 locations in 20 rice growing states in India was investigated. Eighty-five strains of A. flavus were isolated from the discolored rice grains and tested for their AFB1 producing potential on different agar media. Among these, 43 strains were identified as AFB1 producers (ranging 0.2 – 40 µg/g agar). All the 43 strains of A. flavus produced AFB1 on yeast extract sucrose agar media (YES). However, 65% of the strains produced AFB1 on Czapek's agar, 53% of the strains on potato dextrose agar (PDA) and none of the strains on Aspergillus flavus and parasiticus agar media (AFPA). The strain, DRAf 009 produced maximum AFB1 (4.0 – 40 µg/g agar) on all the agar media tested. Five strains of A. flavus producing high amounts of AFB1 identified in agar media were evaluated for their AFB1 production on milled rice cultivars. The five strains produced AFB1 on all the rice cultivars. Out of 5 strains, the DRAf 009 produced maximum AFB1 (386 – 415 µg/g grain) on all the rice cultivars tested.
  AFRICAN JOURNAL OF BIOTECHNOLOGY 08/2009; 8:3303-3308. · 0.57 Impact Factor