Use of Asian selected agricultural byproducts to modulate rumen microbes and fermentation

In the last five decades, attempts have been made to improve rumen fermentation and host animal nutrition through modulation of rumen microbiota. The goals have been decreasing methane production, partially inhibiting protein degradation to avoid excess release of ammonia, and activation of fiber digestion. The main approach has been the use of dietary supplements. Since growth-promoting antibiotics were banned in European countries in2006, safer alternatives including plant-derived materials have been explored. Plant oils, their component fatty acids,plant secondary metabolites and other compounds have been studied, and many originate or are abundantly available in Asia as agricultural byproducts. In this review, the potency of selected byproducts in inhibition of methane production and protein degradation, and in stimulation of fiber degradation was described in relation to their modes of action. In particular, cashew and ginkgo byproducts containing alkylphenols to mitigate methane emission and bean husks as a source of functional fiber to boost the number of fiber-degrading bacteria were highlighted. Other byproducts influencing rumen microbiota and fermentation profile were also described. Future application of these feed and additive candidates is very dependent on a sufficient, cost-effective supply and optimal usage in feeding practice.

Phylogenetically Distinct Cellulose Synthase Genes Support Secondary Wall Thickening in Arabidopsis Shoot Trichomes and Cotton Fiber

Through exploring potential analogies between cotton seed trichomes （or cotton fiber） and arabidopsis shoot trichomes we discovered that CesAs from either the primary or secondary wall phylogenetic clades can support secondary wall thickening. CesA genes that typically support primary wall synthesis, AtCesA 1,2,3,5, and 6, underpin expansion and secondary wall thickening of arabidopsis shoot trichomes. In contrast, apparent orthologs of CesA genes that support secondary wall synthesis in arabidopsis xylem, AtCesA4,7, and 8, are up-regulated for cotton fiber secondary wall deposition. These conclusions arose from： （a） analyzing the expression of CesA genes in arabidopsis shoot trichomes; （b） observing birefringent secondary walls in arabidopsis shoot trichomes with mutations in AtCesA4, 7, or 8; （c） assaying up-regulated genes during different stages of cotton fiber development; and （d） comparing genes that were co.expressed with primary or secondary wall CesAs in arabidopsis with genes up- regulated in arabidopsis trichomes, arabidopsis secondary xylem, or cotton fiber during primary or secondary wall deposition. Cumulatively, the data show that： （a） the xylem of arabidopsis provides the best model for secondary wall cellulose synthesis in cotton fiber; and （b） CesA genes within a ＂cell wall toolbox＂ are used in diverse ways for the construction of particular specialized cell walls.

Identification and Profiling of Known and Novel Fiber MicroRNAs during the Secondary Wall Thickening Stage in Cotton(Gossypium hirsutum) via High-Throughput Sequencing

Upland cotton （Gossypium hirsutum L.） is an allotetraploid species originated from interspecific hybridization between AA-genome diploid （G. arboretum） and DD-genome diploid （G. raimondii） （Wendel et al., 1992）. Cotton fibers are single-celled trichomes that emerge from the ovule epidermal cells. Indexed by the number of days post-anthesis （dpa）, fiber morphogenesis includes four distinct but overlapping steps： initiation （0-3 dpa）, elongation （3-20 dpa）, secondary cell wall thickening （15-45 dpa） and maturation （40-60 dpa） （Yang et al., 2008, Du et al., 2013）. The efficiency and duration of each morphogenesis stage is important to the quality attributes of the mature fiber. Cell elongation is critical for fiber length, whereas secondary cell wall thickening is important for fiber fineness and strength （Meinert and Delmer, 1977）.

Adsorption characteristics of surfactants on secondary wood fiber surface

Surfactant residues in recycled wood fiber from the deinking process can have impact on the subsequent bleaching and papermaking processes by increasing bleaching agents and disturbing papermaking wet-end chemistry.In this paper,the fundamental mechanism of surfactants adsorption characteristics on secondary fiber surface was studied.The adsorption isotherms and kinetics of an anionic surfactant,sodium dodecyl benzene sulfonate(SDBS)and a non-ionic surfactant,Triton X-100(TX-100)on secondary fiber surface with or without the presence of electrolytes(Mg^(2+)ions)were studied by using spectrophotometric methods.Results showed that the adsorption isotherm of SDBS could be subdivided into four regions,and the adsorption of SDBS was increased with the presence of Mg^(2+)ions.While for TX-100,the adsorption isotherm showed typically Langmuir-type adsorption,and its adsorption was decreased with the presence of Mg^(2+)ions.Kinetic analysis indicated that the adsorption processes both fit pseudo-second-order model well.The adsorption rate of both surfactants was affected by the initial surfactant concentration,electrolyte and temperature.The activation parameters confirmed that the adsorption processes of both surfactants were typically diffusion-controlled and endothermic at a temperature range commonly used for current flotation deinking processes.SDBS and TX-100 mainly adsorbed to the hydrophobic sites of secondary fibers surface,which decreased the fiber hydrophobicity and reduced the fiber loss in the flotation deinking process.The results suggested that the concentration of Mg^(2+)ions should be maintained at a low level when SDBS was used in the flotation process.