Broda, M. | Search bioRxiv

bioRxiv2021

Potato juice, a starch industry waste, as a cost-effective medium for the biosynthesis of bacterial cellulose

The unique properties of bacterial cellulose (BC) make it of great interest for numerous branches of industry. Nevertheless, the high cost of the dedicated, microbiological medium used for BC production significantly hinders possibility of widespread use. Searching for an alternative, we turned our attention to potato tuber juice (PJ), a major waste product of the potato starch industry. We verified the possibility of using PJ as a cost-effective, ecological-friendly medium that yielded BC with properties equivalent to those from conventional commercial Hestrin-Schramm medium. The BC yield from PJ medium (>4 g/L) was comparable, despite the lack of any pre-treatment. Likewise, the macro- and microstructure, physicochemical parameters, and chemical composition showed no significant differences between PJ and control BC. Importantly, BC obtained from PJ was not cytotoxic against fibroblast cell line L929 in vitro and did not contain any hard-to-remove impurities. These are very important aspects from an application standpoint, particularly in biomedicine. Therefore, we conclude that using PJ for BC biosynthesis is a path towards significant valorization of an environmentally problematic waste product of the starch industry and can help ultimately lower BC production costs. HighlightsO_LIPotato juice (PJ) was used as a culture medium for cellulose-synthesizing bacteria. C_LIO_LIPJ was suitable as source of nutrients and did not required any pre-treatment. C_LIO_LIYield of BC from PJ was equivalent to that obtained from conventional HS. C_LIO_LIPJ-BC did not differ from conventionally produced HS-BC in terms of its properties. C_LIO_LIPJ-BC can be used in the same applications as commercially produced BC. C_LI Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=88 SRC="FIGDIR/small/452442v1_ufig1.gif" ALT="Figure 1"> View larger version (25K): org.highwire.dtl.DTLVardef@5d10c1org.highwire.dtl.DTLVardef@1f71718org.highwire.dtl.DTLVardef@10d4976org.highwire.dtl.DTLVardef@1521f0a_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioengineering↗

bioRxiv2021

Defects in autophagy lead to selective in vivo changes in turnover of cytosolic and organelle proteins in Arabidopsis

Identification of autophagic protein cargo in plants by their abundance in autophagy related genes (ATG) mutants is complicated by changes in both protein synthesis and protein degradation. To detect autophagic cargo, we measured protein degradation rate in shoots and roots of Arabidopsis atg5 and atg11 mutant plants. These data show that less than a quarter of proteins changing in abundance are probable cargo and revealed roles of ATG11 and ATG5 in degradation of specific cytosol, chloroplast and ER-resident proteins, and a specialized role for ATG11 in degradation of proteins from mitochondria and chloroplasts. Our data support a role for autophagy in degrading glycolytic enzymes and the chaperonin containing T-complex polypeptide-1 complex. Autophagy induction by Pi limitation changed metabolic profiles and the protein synthesis and degradation rates of atg5 and atg11 plants. A general decrease in the abundance of amino acids and increase in several secondary metabolites in autophagy mutants was consistent with altered catabolism and changes in energy conversion caused by reduced degradation rate of specific proteins. Combining measures of changes in protein abundance and degradation rates, we also identify ATG11 and ATG5 associated protein cargo of low Pi induced autophagy in chloroplasts and ER-resident proteins involved in secondary metabolism. Single Sentence SummaryProtein cargo of autophagy in plants can be discovered by identifying proteins that increase in abundance and decrease in degradation rate in mutants deficient in autophagy machinery

plant biology↗