Comparative studies of fungi associated with sea foods in different wetlands of Akwa Ibom State

2020 ◽  
Vol 34 (1) ◽  
pp. 41-47
Author(s):  
I.N. Bassey ◽  
N.U. Asamudo

The study investigated fungi associated with sea foods, fish (Pellonula leonensis) and crayfish (Parapandalus pritis) from different wetlands (Ibeno, Ikot Abasi, Eket and Itu) in Akwa Ibom State. Samples were collected and cultured on Potato Dextrose Agar (PDA) and the isolated fungi were identified using molecular technique. Based on PCR amplification, sequencing of the internal transcribed spacer and phylogenetic analysis, the fungi identified were: Aspergillus niger, A. felis, A. foetidus, A. aculeatus, A. japonicus, A. flavus, A. tamari, A. terreus, Penicilium citrinum, Candida tropicalis and Trametes polyzona. The most commonly isolated fungi from fish for the four locations were A. niger (52.8) in Itu, P. citrinum (51.7) in Ibeno, A. foetidus (53.5) in Ikot Abasi and A. aculeatus (51.6) in Eket. For samples of crayfish, the most commonly isolated fungi were A. niger (25.1) in Itu and A. foetidus (20.1) in Ikot Abasi. Generally, Ibeno recorded the highest frequencies of fungal isolates while Ikot Abasi had the least. Percentage occurrence of fungi isolated from fish samples were significantly higher (p<0.05) when compared with those isolated from crayfish samples. The presence of these fungi showed that sea foods were exposed to an increasing number of virulent infectious diseases in natural populations, and fungal-like diseases can cause some of the most severe die-offs and extinctions ever witnessed in wild species thus jeopardizing food security Keywords: Fungi, Sea food, Wetland, Aspergillus, Fish.

Author(s):  
S. M. Yahaya ◽  
A. B. Kamalu ◽  
M. U. Ali ◽  
M. Lawan ◽  
Y. S. Ajingi ◽  
...  

This research was conducted to determine the fungal pathogens responsible for post harvest losses of pineapple sold at Wudil and Yen lemo markets.  Two samples of pineapples were purchased twice a week from both Wudil and Yanlemo markets for four months. The samples were investigated for the presence of fungal pathogen using standard microbiological methods. The methods involve mounting small portion of pineapple in the plate containing Potato dextrose agar to isolate the fungi. Three fungal pathogens belonging to Aspergillus species were isolated, and Aspergillus niger had the highest frequency of occurrence of (50%). Followed by A. flavus with (27%). The A. fumigatus had the lowest frequency of occurrence of (23%). The differences between the fungal isolates recorded were significantly different (P<0.05) between the two markets, where higher fungal isolates were recorded at Yanlemo market 159 (40.6%) and Wudil 38 (9.71%). The study showed that the post harvest losses of pine apple in the two markets are attributed to fungal infection. Therefore, safe guarding the two markets from debris and dumps of rotten fruits and vegetable may assist in reducing fungal inoculums in the two markets.


2020 ◽  
Vol 4 (3) ◽  
pp. 224-229
Author(s):  
A. Nuhu ◽  
Ibrahim Hussaini ◽  
S. Gide ◽  
G. Anas ◽  
A. Madika

One of the limitations of large scale application of laccase (EC 1.10.3.2) is the inability to produce them in large quantity at an affordable cost. This study was carried out to screen indigenous fungi for their ability to produce laccase using the locally available substrate. Five soil samples were collected and diluted serially, 0.1 mL of the 10-5 and 10-6 dilutions were inoculated onto Potato dextrose agar (PDA) plates. The fungal isolates were identified based on their macroscopic and microscopic characteristics. The isolates were then screened for laccase production by growing them on PDA containing tannic acid as an indicator compound. The laccase producing isolates were further screened for their ability to utilize corn cob as a substrate for laccase production. Ten fungal species were isolated and identified as Trichoderma viridae (3), Trichoderma harzianum (3), Aspergillus niger (2), Fusarium sp. (1) and Penicillium sp. (1). Only two of the isolates namely T. viridae and T. harzianum were found to be laccase producers. Both laccase producing fungal species were able to utilize corn cob as substrate for laccase production. T. viridae had higher enzyme activity (2.228 U/mL) than T. harzianum (2.1583 U/mL) after 9 days of incubation. Laccase producing fungi were isolated in this study and they were able to use corn cob as substrate for laccase production.


2016 ◽  
Vol 52 (No. 4) ◽  
pp. 250-253 ◽  
Author(s):  
Ivanová Helena ◽  
Hrehová Ľudmila ◽  
Pristaš Peter

During 2014–2015, samples from ten 20–25 years old pine (Pinus ponderosa var. jeffreyi) trees showing wilt symptoms were collected from the Arborétum Mlyňany park. A disease was observed on 20% of the trees. The first symptoms are wilting, stunting, chlorosis, and discolouration of needles, which turned yellow on affected twigs, then red and finally they fell off. Isolations of the pathogen were done from the discoloured tissues of needles (twenty samples from each tree) on Potato Dextrose Agar. Colonies of the fungus (3–4 Petri dishes from each tree) were initially aerial, white or slightly violet, but with age they became red and red pigments were produced in agar. The observed micromorphological characteristics of the fungus, such as presence of simple and proliferating conidiophores with polyphialides, microconidia, macroconidial shape, and chlamydospore presence matched the description of Fusarium sporotrichioides. The identity of the fungus was confirmed by phylogenetic analysis of internal transcribed spacer (ITS) sequences. Sequence comparisons placed the fungus to the species F. sporotrichioides with similarity of 99.6% at the ITS sequence level.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Carmen Blanco-Fernandez ◽  
Alba Ardura ◽  
Paula Masiá ◽  
Noemi Rodriguez ◽  
Laura Voces ◽  
...  

AbstractDespite high effort for food traceability to ensure safe and sustainable consumption, mislabeling persists on seafood markets. Determining what drives deliberate fraud is necessary to improve food authenticity and sustainability. In this study, the relationship between consumer’s appreciation and fraudulent mislabeling was assessed through a combination of a survey on consumer’s preferences (N = 1608) and molecular tools applied to fish samples commercialized by European companies. We analyzed 401 samples of fish highly consumed in Europe and worldwide (i.e. tuna, hake, anchovy, and blue whiting) through PCR-amplification and sequencing of a suite of DNA markers. Results revealed low mislabeling rate (1.9%), with a higher mislabeling risk in non-recognizable products and significant mediation of fish price between consumer´s appreciation and mislabeling risk of a species. Furthermore, the use of endangered species (e.g. Thunnus thynnus), tuna juveniles for anchovy, and still not regulated Merluccius polli hake as substitutes, points towards illegal, unreported and/or unregulated fishing from African waters. These findings reveal a worrying intentional fraud that hampers the goal of sustainable seafood production and consumption, and suggest to prioritize control efforts on highly appreciated species.


Plant Disease ◽  
2021 ◽  
pp. PDIS-06-20-1290
Author(s):  
Juliana S. Baggio ◽  
Bruna B. Forcelini ◽  
Nan-Yi Wang ◽  
Rafaela G. Ruschel ◽  
James C. Mertely ◽  
...  

Pestalotiopsis-like species have been reported affecting strawberry worldwide. Recently, severe and unprecedented outbreaks have been reported in Florida commercial fields where leaf, fruit, petiole, crown, and root symptoms were observed, and yield was severely affected. The taxonomic status of the fungus is confusing because it has gone through multiple reclassifications over the years. Morphological characteristics, phylogenetic analyses, and pathogenicity tests were evaluated for strawberry isolates recovered from diseased plants in Florida. Phylogenetic analyses derived from the combined internal transcribed spacer, β-tub, and tef1 regions demonstrated that although there was low genetic diversity among the strawberry isolates, there was a clear separation of the isolates in two groups. The first group included isolates recovered over a period of several years, which was identified as Neopestalotiopsis rosae. Most isolates recovered during the recent outbreaks were genetically different and may belong to a new species. On potato dextrose agar, both groups produced white, circular, and cottony colonies. From the bottom, colonies were white to pale yellow for Neopestalotiopsis sp. and pale luteous to orange for N. rosae. Spores for both groups were five-celled with three median versicolored cells. Mycelial growth and spore production were higher for the new Neopestalotiopsis sp. isolates. Isolates from both groups were pathogenic to strawberry roots and crowns. However, the new Neopestalotiopsis sp. proved more aggressive in fruit and leaf inoculation tests, confirming observations from the recent outbreaks in commercial strawberry fields in Florida.


2021 ◽  
Vol 6 (1) ◽  
pp. 91-98
Author(s):  
A. Bello ◽  
◽  
J. B. Ameh ◽  
D. A. Machido ◽  
A. I. Mohammed-Dabo

Laccases are oxidases with broad substrate specificity and ability to oxidize various phenolic and non-phenolic compounds. This study was carried out to isolate and characterizes laccase producing fungi from environment samples. Soil and decaying wood samples were collected from different locations within Ahmadu Bello University, Zaria Main campus. Suspensions of the samples (1 g in 10 mL sterile distilled water) were serially diluted, inoculated onto Potato Dextrose Agar (PDA) containing 0.01% Chloramphenicol and incubated for 7 days at 30oC.The fungal isolates were characterized macroscopically and microscopically with the aid of an atlas. The identified fungal isolates were screened for laccase production by inoculating onto PDA containing 0.02% Guaiacol, 1mM ABTS (2 2’-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) and 0.5% Tannic acid as indicator compounds and incubated at 250C for 7 days. The laccase producing isolates were confirmed molecularly by ITS rDNA sequence analysis using the FASTA algorithm with the Fungus database from the European Bioinformatics Institute (EBI).A total of 25 fungal species (11 from soil and 14 from decaying wood samples) were isolated. Two isolates from the soil origin identified as Curvularia lunata SSI7 (Accession No. QIE06317.1) and Fusarium clade VII SSI3 (Accession No. GQ505677) were found to produce laccase where Curvularia lunata SSI7 was able to oxidize all the indicator compounds used for the screening. Fusarium clade VII SSI3 was able to oxidize only 0.5% Tannic acid. Laccase producing Curvularia lunata and Fusarium clade VII were isolated from soil samples collected from ABU Zaria Main Campus. Keywords: laccase, fungi, soil, decaying wood


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