Comparison of the Bacterial Microbiota in a Bale of Collected Cardboard Determined by 454 Pyrosequencing and Clone Library

Abstract

Biofouling, the accumulation of microorganisms, is a major problem in paper mills processing paper and cardboard. This leads to the production of lower quality recycled products. Several studies have focused on the microbial content in the paper mill and the final products. Our aim was to determine the microbial biota in a bale of collected cardboard prior to entering the paper mill. Total genomic DNA was isolated and analyzed using two different methods for comparison purposes: 454 pyrosequencing and clone library. A total of 3268 V6-V8 454 pyrosequencing reads and 322 cloned V6-V8 16S rRNA nucleotide sequences were obtained. Both methods showed the presence of three major bacterial genera: Bacillus, Solibacillus and Paenibacillus, all members of the spore-forming phylum Firmicutes. Pyrosequencing, however, revealed a richer and more diverse bacterial community than clone library. It showed the presence of additional minor Firmicute genera and of a small number of Proteobacteria. The sorting at the recycling plant, the storing, and the processing at the paper mill, the end uses, will all contribute to the bacterial microbiota present in a bale of collected cardboard as revealed here.

Fiber-based food packaging materials in view of bacterial growth and survival capacities

“…The isolates C. firmus and N. circulans, on the other side, could only grow in two materials that contained recycled fibers, and growth of B. cereus was restricted to a material composed entirely of recycled fibers. These three species, belonging to the Bacillaceae, are typical packaging inherent bacteria (Suihko et al, 2004;Lalande et al, 2014;Schmid et al, 2021) and appeared to be specifically adapted to the composition of the recycled fibers materials. Evaluation of spore germination is essential, since Frontiers in Microbiology 10 frontiersin.org endospore forming bacteria comprise the major part of packaging inherent bacteria (Väisänen et al, 1991;Suihko et al, 2004).…”

“…The presence of bacteria in fiber-based packaging materials has been intensively studied covering the raw materials, the manufacturing environment and the final product ( Väisänen et al, 1998 ; Zumsteg et al, 2017 ). Studies on packaging materials revealed a predominance of Gram-positive, mesophilic, endospore-forming bacteria, mostly belonging to the family of Bacillaceae ( Suihko et al, 2004 ; Lalande et al, 2014 ), including food relevant Bacillus cereus ( B. cereus ) ( Schmid et al, 2021 ). Within the last years, the COVID-19 pandemic has drawn public attention to possible cross-contamination events through packaging materials ( De Oliveira et al, 2021 ).…”