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The effect
of reuse of unhairing-liming residual floats through
regeneration on the microorganism number
Binnur Meriçli Yapici1*,
Ali Nail Yapici2 and Ece Keçici1
1Çanakkale
Onsekiz Mart University, Faculty of Science and Arts,
Biology Department, Basic and Industrial Microbiology
Section, 17100 Çanakkale, Turkey.
2Çanakkale
Onsekiz Mart University, Biga Vocational College, 17200 Biga,
Çanakkale, Turkey
*Corresponding author. E-mail: yapici69@gmail.com. Tel:
+(90) 286 2180018-1866. Fax:+(90) 286 2180533.
Abbreviations:
ULP, Unhairing-liming process; and SP, soaking
process.
Accepted 11 August, 2008 |
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Even though microorganism load was mostly ignored in the
unhairing-liming process due to extremely high pH values, it
is a question to answer when unhairing-liming residual
floats are reused through regeneration. The objective of
this paper was to determine the number of total aerobic
mesophilic bacteria and of proteolytic, lypolytic, aerobic
spore-forming bacteria, and of total aerobic fungi (mould
and yeast), proteolytic and lypolytic fungi in each
unhairing-liming residual float reused ten times through
regeneration. Enumeration of bacteria and fungi was done in
three different concentrations of NaCl [0, 5, and 10%
(w/v)]. The experiments were carried out with and without
antimicrobial agents (experimental and control). In this
study, generally, the values obtained from experimental
samples were detected to be lower than control samples. For
experimental samples, when all the NaCl concentrations were
taken into account, the minimum and maximum numbers of total
aerobic mesophilic bacteria and of proteolytic, lypolytic,
aerobic spore-forming bacteria were found as follows: 2.0x101
– 3.9x102 cfu.mL-1, 1.0x101
– 4.1x102 cfu.mL-1,
2.0x101 – 5.4x102 cfu.mL-1
and 1.0x101 – 2.0x102 cfu.mL-1,
respectively. In these samples, it was found out that
the minimum and maximum numbers of total aerobic fungi and
of proteolytic and lypolytic fungi were 3.0x101 –
2.8x103 cfu.mL-1, 1.0x101 –
1.2x103 cfu.mL-1, and 5.0x101
– 3.5x103 cfu.mL-1, respectively. In
the study, there is a significant finding that the numbers
of fungi were higher than those of bacteria. In addition,
when bactericide and fungicide were added into the soaking
processes and when unhairing-liming residual floats were
reused ten times via regeneration, it was revealed that the
numbers of bacteria and fungi can be controlled.
Key words:
Unhairing-liming process, reusing, leather industry,
environment, bacterial and fungal numbers. |
