The effect of reuse of unhairing-liming residual floats through regeneration on the microorganism number

  • BM Yapici
  • AN Yapici
  • E Keçici
Keywords: Unhairing-liming process, reusing, leather industry, environment, bacterial and fungal numbers.

Abstract

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.
Section
Articles

Journal Identifiers


eISSN: 1684-5315