15 research outputs found
Extenuating mycotoxin contamination in spices: detection, regulatory frameworks and preventive strategies
Get PDFMycotoxins are secondary metabolites produced by fungi, primarily from the genera Aspergillus, Fusarium, Penicillium and Alternaria. The attention is on the existence of mycotoxin compounds in food substances that jeopardize public health and it is directed to systematic regulation to overcome these issues. Pathogenic fungi, including Aspergillus, Penicillium and Fusarium species, infiltrate spice crops during the pre-harvest, postharvest and storage stages. These fungi create toxic secondary metabolites called mycotoxin. The reviews' intend to examine the prevalence, types and levels of mycotoxins commonly found in spices, including aflatoxins, ochratoxin A and fumonisins. The study highlights the factors that influence mycotoxin contamination, such as environmental conditions, agricultural practices and storage methods. Analytical techniques for detecting mycotoxins, including chromatography and immunoassays, are evaluated for efficacy and sensitivity. It also discusses the regulatory frameworks and safety standards established by international bodies like the Codex Alimentarius Commission to mitigate mycotoxin risks. In addition to these regulatory measures, mycotoxin detection needs to be addressed before framing the standards. The preventive strategies and mitigation measures, including good agricultural practices (GAP), proper drying, storage conditions and biocontrol agents, were explored based on previous research conducted earlier. This comprehensive review underscores the critical importance of implementing integrated approaches combining advanced detection methods, harmonized regulatory standards and preventive strategies to ensure the safety and quality of spices in the global food supply chain
Biology and predatory potential of chrysopids on invasive coconut rugose spiralling whitefly Aleurodicus rugioperculatus Martin
Get PDF814-818The relatively new invasive rugose spiralling whitefly (RSW) Aleurodicus rugioperculatus (Hemiptera: Aleyrodidae) has become a serious threat to oil palm, particularly coconut plantation, in southern India. Here, we report biology and foraging potential of predatory neuropteran Green lace wings Chrysoperla zastrowi sillemi (Esben-Petersen) and Mallada boninensis (Okamoto) (Chrysopidae) on against RSW. Results revealed that A. rugioperculatus served as a suitable host for the both chrysopid predators. C. z. sillemi completed its life cycle in 19.91±1.90 days with a larval (grub) period of 9.44±3.91 days and adult longevity was 24.10±1.87 days. The developmental period of M. boninensis was 22.3±2.93 days, with a larval period of 11.85±1.71 days, while the adult longevity was 19.25±1.52 day. In the laboratory experiment, all the larval stages of the predators were observed to feed on A. rugioperculatus. It was observed that the 3rd instar grub of C. zastrowi sillemi with the developmental period of 3.24±1.73 days consumed a maximum of 313.2 whiteflies (all the life stages) followed by second and 1st instar grub stages of the predator, which consumed mean number of 200.2 and 140.2 eggs and nymphs of A. rugioperculatus, respectively during their developmental period of 3.58±1.84 and 2.62±1.34 days, respectively. In the case of M. boninensis, a single grub could consume a total of 929.8 whiteflies (both eggs and nymphal stages) during its total larval period of 9.44±3.91 days
Investigating the Ochratoxin Production Potential of Aspergillus spp in Indian Rice: A Comprehensive Study
No full textRice (Oryza sativa), worldâs second most important cereal crop and most commonly consumed grains in the world. Though more than 100,000 species of fungi are known to exist, majority of mycotoxigenic fungi belong to the species of Aspergillus, Penicillium, and Fusarium. Among Aspergillus spp, Aspergillus niger and Aspergillus ochraceus are known to produce Ochratoxin A (OTA), a notable mycotoxin having adverse effects due to ubiquitous presence, renal toxicity and lengthy persistence. Totally eighty-one samples including unpolished (n = 36) and polished rice samples (n = 45) were collected in various districts of Tamil Nadu to identify ochratoxigenic fungi particularly Aspergillus spp. Out of 81 samples, 62 % (50/81) of samples including unpolished (n = 24) and polished rice (n = 26) documented the occurrence of ochratoxigenic fungi. Extraction of OTA was carried out by agar plug method and the ability of fungus to produce OTA was quantified by RP HPLC-FLD analysis. Among the fungal genera, Aspergillus spp (80 %) recorded the predominant fungus in rice. Molecular confirmation of ochratoxigenic fungi A. niger and A. ochraceus isolates was performed by 18s rDNA analysis. OTA producing ability by RP HPLC-FLD analysis revealed A. ochraceus of section Circumdati recorded the highest OTA production than A. niger isolates of section Nigri. The concentration range of OTA by A. ochraceus vary between 12.33 - 196.84 ng/g and 0.18 - 2.82 ng/g respectively in A. niger isolates. Among the A. ochraceus isolates, potent isolate AO 9 documented the highest OTA production (196.84 ng/g) followed by AO 6 (104.74 ng/g). Similarly, in A. niger AN 1 showed highest production of 2.82 ng/g followed by AN 5 isolate (1.25 ng/g) respectively. The objective of the study is to determine and quantify the ochratoxin production potential of Aspergillus spp in Indian rice by RP HPLC-FLD analysis. The occurrence of Aspergillus spp in rice and the subsequent ochratoxin production raise concern about possible health risk to animal and human environment upon consumption. Hence there is need for improved storage practices and regular monitoring to prevent the prevalence of Aspergillus fungus and OTA contamination in rice supply chain
Evaluation of Suitable Polymers for the Development of High-Concentrated Liquid Biofertilizers
No full textAn improvement in the present liquid formulation of biofertilizer is essential to expand its shelf life and enhance the bioefficacy potential of the inoculated crops. Here, we screened ten different water-soluble polymers for their feasibility as cell protectants in liquid biofertilizers for the duration of three months. The physio-chemical properties and Escherichia coli survival assay experiments identified five potential polymers: hydroxypropyl methylcellulose, polyvinyl alcohol, and natural polymers extracted from seaweed, red algae, and brown algae. These five polymers' aqueous solutions comply with the standard parameters of liquid biofertilizers. Further, these polymers were compared with standard liquid biofertilizer diluting medium (phosphate buffer with glycerol) for the shelf life of two biofertilizer strains, viz., Azospirillum lipoferum (Az204) and Bacillus megaterium var. phosphaticum (Pb1). All the polymers had high cell viability up to 60 days after incubation. In conclusion, the results suggest that these polymers could be effective encapsulating agents to improve the quality of liquid biofertilizers
Quantification of Antimicrobial Compounds Produced by Lactic Acid Bacteria Isolated from Pulses
No full textIn this study, 11 LAB isolates were isolated from the pulses (green gram and black gram) were tested for biochemical characteristics (catalase, MR-VP, citrate utilization, nitrate reduction) based on these tests four isolates were evaluated for their antimicrobial activity against three prominent pathogens: Escherichia coli, Pseudomonas aeruginosa, and Aspergillus flavus NRRL3357 under different pH 9 (5.5, 6.5, 7.5 and 8.5) and temperature (17ÂșC, 27ÂșC, and 40ÂșC). Among the four isolates, one isolate LB4 exhibited notable antimicrobial efficacy against all three pathogens under pH (6.5) 8.1± 0.6 mm, 8.3 ± 0.5 mm, and 6.6 ± 0.8 mm respectively. Optimum antimicrobial activity showed at temperature 27Âș against same pathogens the zone of inhibition mean values 10± 0.9 mm, 5.0± 0.6 mm, 8.3± 1.2 mm respectively. LB4 isolate was tested for quantification of key metabolites after three days of incubation, lactic acid, acetic acid, and hydrogen peroxide. Lactic acid (4.6 g/l) and acetic acid (4.8 g/l) were consistently produced in higher amounts, while hydrogen peroxide production remained relatively low (0.58 g/l) by the LB4 isolate. The results indicated the intricate relationship between antimicrobial activity, environmental factors, and metabolite production, emphasizing the promising role of this isolate in combating microbial infections under diverse conditions
The metabolic response of suspension-cultured cells from blast-resistant and -susceptible rice (Oryza sativa L.) genotypes to a Pyricularia oryzae elicitor
No full textEngineering resistance against Tobacco streak virus (TSV) in sunflower and tobacco using RNA interference
No full textThe coat protein (CP) gene of Tobacco streak virus (TSV) from sunflower (Helianthus annuus L.) was amplified, cloned and sequenced. A 421 bp fragment of the TSV coat protein gene was amplified and a gene construct encoding the hairpin RNA (hpRNA) of the TSV-CP sequence was made in the plasmid pHANNIBAL. The construct contains sense and antisense CP sequences flanking a 742 bp spacer sequence (Pdk intron) under the control of the constitutive CaMV35S promoter. A 3.6 kb Not I fragment containing the hpRNA cassette (TSV-CP) was isolated from pHANNIBAL and sub-cloned into the binary vector pART27. This chimeric gene construct was then mobilized into Agrobacterium tumefaciens strain LBA4404 via triparental mating using pRK2013 as a helper. Sunflower (cv. Co 4) and tobacco (cv. Petit Havana) plants were transformed with A. tumefaciens strain LBA4404 harbouring the hpRNA cassette and in vitro selection was performed with kanamycin. The integration of the transgene into the genome of the transgenic lines was confirmed by PCR analysis. Infectivity assays with TSV by mechanical sap inoculation demonstrated that both the sunflower and tobacco transgenic lines exhibited resistance to TSV infection and accumulated lower levels of TSV compared with non-transformed controls
Selective Isolation and Characterization of Phytophthora infestans from Potatoes Using Rye Agar Media in India
No full textPhytophthora infestans is a pathogen that causes late blight, a major disease of potatoes. The isolation of P. infestans from infected potato plants using agar media has been challenging. This study investigated the use of Rye A and Rye B agar media for the isolation of P. infestans from infected potato tubers collected from the Nilgiris district of Tamil Nadu during 2022. The media were evaluated for hyphal growth, sporangial production, oospore formation, and long-term storage of P. infestans. Phenotypic diagnosis based on cultural and morphological characteristics confirmed the identity of P. infestans. The results were confirmed by a molecular identification test using primers specific to P. infestans. Pathogenicity tests were carried out to assess the virulence of the isolates. This study provides a useful protocol for the selective isolation and characterization of P. infestans, the potato late blight pathogen
Metabolic Biomarker Panels of Response to Fusarium Head Blight Infection in Different Wheat Varieties
No full textDetoxification of aflatoxin B1 by an aqueous extract from leaves of Adhatoda vasica Nees
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