Incidence of mycoflora complexes on retail kolanuts (C. nitida and C ...

Adeniyi et al. .…J. Appl. Biosci. 2012.
<strong>Incidence</strong> <strong>of</strong> myc<strong>of</strong>lora <strong>complexes</strong> on retail kolanuts in Nigeria
Journal <strong>of</strong> Applied Biosciences 56: 4075– 4079
ISSN 1997–5902
<strong>Incidence</strong> <strong>of</strong> myc<strong>of</strong>lora <strong>complexes</strong> on retail kolanuts
(C. nitida and C. acuminata) in North Central Nigeria
Adeniyi D. O*, Kolawole O. O, Oduwaye O. F, Adejobi K. B, Adenuga O. O, Adepoju A. F, Olaniyi O.
O and Anagbogu C. F.
Cocoa Research Institute <strong>of</strong> Nigeria, Km 14, Ibadan-Ijebu Ode Road PMB 5244, Ibadan, Nigeria
*Corresponding author: modeleadeniyi@gmail.com
Original submitted in on 20 th June 2012. Published online at www.m.elewa.org on August 30th 2012.
ABSTRACT
Objectives: The prevalence <strong>of</strong> myc<strong>of</strong>lora associated with retail kolanuts (C. nitida and C. acuminata)
obtained randomly across the North Central States <strong>of</strong> Nigeria was studied.
Methodology and results: Surface sterilized tissues <strong>of</strong> the kolanuts samples were cultured on acidified
Potato Dextrose Agar (PDA) using standard laboratory methods. Twelve fungi isolates, mostly toxigenic
and belonging to nine genera (Aspergillus, Fusarium, Mucor, Lasiodiplodia, Paecilomyces,
Chlamydomyces, Rhizopus, Penicillium and Curvularia) were isolated from the kolanuts tissues. L.
theobromae and F. pallidoroseum were the most predominant isolates and the incidence <strong>of</strong> L. theobromae
on C. nitida was significantly higher (p

Adeniyi et al. .…J. Appl. Biosci. 2012.
<strong>Incidence</strong> <strong>of</strong> myc<strong>of</strong>lora <strong>complexes</strong> on retail kolanuts in Nigeria
physiological effects that are similar to the action <strong>of</strong>
caffeine (Carrillo and Bennitez, 2000). Kola nut is
chewed in Africa for its alkaloid properties which
dispel sleep, thirst and hunger. The nuts are also
used in the pharmaceutical and food industries to
produce cardiac stimulants, laxatives, sedatives
and sodas. The cultivation, processing and storage
<strong>of</strong> the nuts are undertaken in the warm, humid rain
forest zone where there is high mould infection.
However, so highly esteemed are the nuts that
fairly moldy samples are commonly ingested
(Adebajo and Popoola, 2003).
Mould growth is a vital problem encountered by
farmers and retailers in the process <strong>of</strong> preservation
and storage <strong>of</strong> kolanut. Storage <strong>of</strong> kolanut has
always been a laborious and delicate task. Kola
traders were reportedly using the traditional
methods <strong>of</strong> storage (Agbeniyi and Ayodele, 2010).
However, kolanut retailers have a measure <strong>of</strong>
regular removal <strong>of</strong> infested nuts during storage and
get them separated to control and minimize
spread. Peasant processing and packaging
MATERIALS AND METHODS
Collection <strong>of</strong> kolanut samples: Samples <strong>of</strong>
seemingly healthy kolanuts (C.nitida and C.
acuminata) were purchased from retailers in
different locations in the North Central States <strong>of</strong>
Nigeria. The selected locations were; Ilorin and
Offa (Kwara), Kabba and Ayingba (Kogi), Gboko
and Otukpo (Benue), Bida and Minna (Niger), Lafia
and Akwanga (Nassarawa) and Jos and Barkin-
Ladi (Plateau). The kolanuts samples were
collected in a sterile polythene bags, labeled
appropriately and assayed in-vitro within a week <strong>of</strong>
collection.
Isolation and Identification <strong>of</strong> myc<strong>of</strong>lora: The
Potato Dextrose Agar (PDA) was routinely
prepared in the laboratory and acidified with 10%
lactic acid. With the use <strong>of</strong> sterilized scalpel, the
kolanut samples were cut into small pieces <strong>of</strong>
about 3mm in diameter, surface sterilized in 2%
Sodium hypochlorite for 2 minutes and rinsed in
predisposes the kola nuts to mould contamination
which is worsen especially during hawking.
Odebode (1990) reported the susceptibility <strong>of</strong> kola
nuts to fungal infection. However, Agbeniyi et al.
(2000) observed that the contamination <strong>of</strong> healthy
nuts with spores from rotted nuts is <strong>of</strong>ten a greater
economic problem in fresh market producing
areas. Botryodiplodia theobromae has been found
to be the most common single species <strong>of</strong> pathogen
associated with kola. Lasiodiplodia theobromae
has also been described as the causal organism <strong>of</strong>
storage rot which is said to be the most severe
post-harvest disease <strong>of</strong> kola nut. This fungus can
also initiate latent infections on nuts in the field
when harvest is delayed, consequently resulting in
rot during storage. Hence, mycotoxicoses is a
serious concern, which is aggravated by
reluctance <strong>of</strong> consumers to discard fairly moldy nut
samples for its economic value. The objective <strong>of</strong>
this study is therefore to establish the array <strong>of</strong>
myc<strong>of</strong>lora <strong>complexes</strong> associated with retail
kolanuts in the North central states <strong>of</strong> Nigeria.
four changes <strong>of</strong> sterile distilled water. The
sterilized tissues were blotted dry in between
sterile Whatman No 1 filter paper (125mm) and
inoculated into petridishes containing about 20ml
<strong>of</strong> solidified PDA. Each <strong>of</strong> the inoculated samples
was replicated five times. The inoculated plates
were incubated at 28+2 o C, colony-growth was
observed and emerging fungal colonies were subcultured
onto PDA plates to obtain pure cultures.
The isolates were identified after microscopic
examinations and fungi occurrence was recorded.
Frequency <strong>of</strong> occurrence <strong>of</strong> the fungi isolates:
The frequency <strong>of</strong> occurrence <strong>of</strong> the fungal isolates
from the nuts <strong>of</strong> C. nitida and C. acuminata was
determined by calculating the percentage
frequency <strong>of</strong> occurrence <strong>of</strong> isolates by the formula:
Freq. <strong>of</strong> Occurrence =
No. <strong>of</strong> Plates containing Species × 100
No. <strong>of</strong> Plates in Sample
4076

Adeniyi et al. .…J. Appl. Biosci. 2012.
<strong>Incidence</strong> <strong>of</strong> myc<strong>of</strong>lora <strong>complexes</strong> on retail kolanuts in Nigeria
RESULTS
Twelve (12) fungi isolates were cultured from the
C. nitida and C. acuminata samples. They include
Lasiodiplodia theobromae, Aspergillus niger, A.
flavus, A. fumigatus, Mucor spinosus,
Paecilomyces variotii, Chlamydomyces sp.,
Rhizopus spp. F. pallidoroseum, F. moniliforme,
Penicillium sp. and Curvularia sp. (Table 1).
Table 1: Myc<strong>of</strong>lora distribution <strong>of</strong> sample locations
Fungi Ilorin Offa Kabba Ayingba Gboko Otukpo Bida Minna Lafia Akwanga Jos Barkin-
Ladi
A. niger + - + - + - + + - + - +
A. flavus - - - + - - - - + + + -
A. fumigatus - - + + - - + + - - + +
F.pallidoroseum + + + - + + - + - + - -
F. moniliforme + + + - + - + + + - + +
M. spinosus + - + - - - - - - - - +
L. theobromae + + + - + + + - + + - +
P. variotii + + - - - - - - - - - -
Chlamydomyces + - - - - - - - - + - -
sp.
Rhizopus spp. - - + - + + + + + - - +
Penicillium sp. + - + + + - - + - + - -
Curvularia sp. + + + + - - + - - - - -
Present (+), Absent (-)
L. theobromae and F. moniliforme were isolated in
nine locations within the selected areas. A. niger,
Rhizopus spp. and F. pallidoroseum were found in
seven <strong>of</strong> the locations. Penicillium spp. and A.
fumigatus occurred in six locations, while
Curvularia spp was intercepted in five locations. A.
flavus was also isolated in four locations. However,
each <strong>of</strong> P. variotii and Chlamydomyces spp. were
found in two locations. Generally, the highest
incidence <strong>of</strong> fungi <strong>complexes</strong> associated with the
kola nuts samples was found in Kwara State. The
analysis <strong>of</strong> the data obtained from the study
showed that the fungi isolates cultured from C.
nitida differ significantly (p

Adeniyi et al. .…J. Appl. Biosci. 2012.
<strong>Incidence</strong> <strong>of</strong> myc<strong>of</strong>lora <strong>complexes</strong> on retail kolanuts in Nigeria
L. theobromae was significantly higher than other
fungi isolates and there was no significant
difference between the occurrence <strong>of</strong> A. flavus and
F. pallidoroseum. The occurrence <strong>of</strong> F.
moniliforme, A. niger, M. spinosus, P. variotii,
Penicillium sp and Rhizopus spp. were not
significantly different from each other. Curvularia
spp and Chlamydomyces spp were also not
significantly different in their occurrence. However,
the incidence <strong>of</strong> A. fumigatus was not observed in
C. nitida. Unlike the observation made from C.
nitida, the incidence <strong>of</strong> L. theobromae and F.
pallidoroseum differ significantly (p

Adeniyi et al. .…J. Appl. Biosci. 2012.
<strong>Incidence</strong> <strong>of</strong> myc<strong>of</strong>lora <strong>complexes</strong> on retail kolanuts in Nigeria
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