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Item Comparative genome identification of accessory genes associated with strong biofilm formation in Vibrio parahaemolyticus.(Elsevier B.V., 2023-04-01) Wang D; Fletcher GC; Gagic D; On SLW; Palmer JS; Flint SHVibrio parahaemolyticus biofilms on the seafood processing plant surfaces are a potential source of seafood contamination and subsequent food poisoning. Strains differ in their ability to form biofilm, but little is known about the genetic characteristics responsible for biofilm development. In this study, pangenome and comparative genome analysis of V. parahaemolyticus strains reveals genetic attributes and gene repertoire that contribute to robust biofilm formation. The study identified 136 accessory genes that were exclusively present in strong biofilm forming strains and these were functionally assigned to the Gene Ontology (GO) pathways of cellulose biosynthesis, rhamnose metabolic and catabolic processes, UDP-glucose processes and O antigen biosynthesis (p < 0.05). Strategies of CRISPR-Cas defence and MSHA pilus-led attachment were implicated via Kyoto Encyclopedia of Genes and Genomes (KEGG) annotation. Higher levels of horizontal gene transfer (HGT) were inferred to confer more putatively novel properties on biofilm-forming V. parahaemolyticus. Furthermore, cellulose biosynthesis, a neglected potential virulence factor, was identified as being acquired from within the order Vibrionales. The cellulose synthase operons in V. parahaemolyticus were examined for their prevalence (22/138, 15.94 %) and were found to consist of the genes bcsG, bcsE, bcsQ, bcsA, bcsB, bcsZ, bcsC. This study provides insights into robust biofilm formation of V. parahaemolyticus at the genomic level and facilitates: identification of key attributes for robust biofilm formation, elucidation of biofilm formation mechanisms and development of potential targets for novel control strategies of persistent V. parahaemolyticus.Item Influence of age and dietary cellulose levels on ileal endogenous energy losses in broiler chickens(Elsevier Inc. on behalf of Poultry Science Association Inc., 2022-07) Khalil MM; Abdollahi MR; Zaefarian F; Chrystal PV; Ravindran VTwo experiments were conducted to investigate the influence of age and dietary cellulose levels on the ileal endogenous energy losses (IEEL) in broiler chickens. In experiment 1, a glucose-based purified diet was used to determine the IEEL. Titanium dioxide (5.0 g/kg) was added to the diet as an indigestible marker. Six groups of broiler chickens aged 1 to 7, 8 to 14, 15 to 21, 22 to 28, 29 to 35 or 36 to 42 d posthatch, were utilized. With the exception of 1-7 d, the birds were fed a starter (d 1–21) and/or a finisher (d 22–35) diet before the experimental diet was introduced. The diet was randomly allocated to 6 replicate cages, and the number of birds per cage was 12 (d 1–7), 10 (d 8–14), and 8 (d 15–42). The ileal digesta were collected at the last day of each week (d 7, 14, 21, 28, 35, and 42). Bird age had no effect (P > 0.05) on the IEEL estimates. The IEEL estimates ranged from 263 to 316 kcal/kg dry matter intake (DMI) during weeks 1 to 6. In Experiment 2, 4 glucose-based purified diets were developed using 0, 25, 50 and 75 g/kg cellulose. Titanium dioxide (5.0 g/kg) was added to the diets as an indigestible marker. The diets were randomly allocated to 6 replicate cages (8 birds per cage) and fed from 18 to 21 d posthatch and, ileal digesta were collected on d 21. The IEEL estimates of broiler chickens at 21 d of age showed a quadratic response (P < 0.05) to increasing cellulose contents. The lowest IEEL (88 kcal/kg DMI) was recorded for the diet without cellulose and the highest IEEL (430 kcal/kg DMI) was observed for the diet with 75 g/kg cellulose. Overall, the present findings confirmed that the IEEL in broiler chickens can be quantified by feeding a glucose-based purified diet. Broiler age had no influence on the IEEL estimates. The IEEL increased with increasing dietary cellulose contents and the IEEL determined using a purified diet without cellulose represents a better estimate of IEEL.Item Comparison of Cd(II) adsorption properties onto cellulose, hemicellulose and lignin extracted from rice bran(Elsevier Ltd, 2021-06) Wu C; Ren M; Zhang X; Li C; Li T; Yang Z; Chen Z; Wang LRice bran, an underutilized by-product obtained from outer rice layers, has received wide interest due to its abundance, eco-friendliness, and low cost. In this research, cellulose, hemicellulose and lignin as the main components of rice bran were fractionated, and their Cd(II) adsorption capacity, behavior and mechanism were further studied. The adsorption capacity of cellulose for Cd(II) was 5.79 mg/g within the equilibrium time of 10 min, which was 1.8 and 3.6 times those of hemicellulose and lignin, respectively. The Cd(II) adsorption onto cellulose exhibited monolayer surface behavior, whilst the heterogeneous adsorption behavior was observed for hemicellulose and lignin. These differences were related to the discrepancy of morphology and chemical composition in three polymers. The multi-hole sticks morphology of cellulose and porous blocky structure of hemicellulose were observed, while lignin showed compact and agglomerated blocky structure. Cellulose had numerous available adsorption sites including the oxygen-containing functional groups, which bonded with Cd(II) driven by chemical interaction. In conclusion, it highlights that cellulose from rice bran has the great potential of being applied as adsorbent for the Cd(II) removal.Item An investigation of the syntheses of cellulose and agarose derivatives containing sulphate, N-(6-aminohexyl)-2-naphthalenesulphonamide and carboxyl groups for the purification of proteins : a thesis presented in partial fulfilment for the requirements for the degree of Master of Science in Chemistry at Massey University(Massey University, 1988) Koh, Thiam SengThe syntheses of three different cellulose and agarose derivatives were investigated, namely, cellulose sulphate, N-(6- aminohexyll-2-naphthalenesulphonamide (2-ANS) cellulose and cellulose and agarose with multiple carboxyl groups. In the case of cellulose sulphate, an attempt was made to find a sulphating reagent and conditions for a commercially convenient method of preparing a cellulose derivative with a sulphate substitution level of 3.5 meq/g. This synthesis was found to require the control of at least one of the following factors: (a) water present in the system, (b) the quantity of sulphating reagent and (c) temperature. The stability of the sulphated cellulose in 0.08M sodium hydroxide at 83°C over 28 days was also evaluated. It was found that the sulphate substitution level decreased linearly over 4 weeks at the rate of 1% per day. Two routes of preparing 2-ANS-cellulose derivative were studied, namely, (1) the coupling of 2-ANS to epoxide activated cel lulose and (2) the coupling of 2-naphthalene sulphonyl chloride (2-NSCl) to diaminohexyl (DAH)-cellulose. Both methods of synthesis were found to be equally feasible. However, the former method required the prior multi-step preparation of 2-ANS, while the latter method was carried out stepwise on the cellulose matrix. The excess reagents were readily washed away before the next step was undertaken. Also, the preparation of 2-NSCI from sodium 2-naphthalene sulphonate was quantitative. The capacity of these 2-ANS-cellulose derivatives for bovine serum albumin (BSA) was also investigated. The products prepared by method 1 showed a much lower capacity (0.05 - 0.38 gBSA/g) for BSA than those prepared by method 2 (0.49 - 0.78 gBSA/g). The syntheses of cellulose and agarose derivatives containing alpha (A)- and beta (B)-citrylhexamethylenediamine (CM,D), aspartic acid (Asp) and 6-aminohexylaspartate (Asp-AH) groups were investigated using both epoxide and 1,1'-carbonyldiimidazole (CDl) activation procedures. The use of these products for the purification of bovine lactoferrin (Lf) was assessed. The nature of the binding action of Lf to the CM,D-matrices was also studied. It was found that (a) high CM,D substitution level on the matrix, (b) high porosity of the matrix and (c) the removal of additional cationic properties from the matrix by replacing the basic nitrogen linkage resulting from the epoxide activation by a non-basic urethane linkage resulting from CDI activation, led to an increase in the strength of Lf binding to the derivative. The results also suggested that the Lf binding was predominantly ionic in nature. Finally, it was found that Lf purification on A-CM,D-agarose gave a product of higher purity than that on Asp-agarose and Asp-AH-agarose.Item The effect of lipid on the digestion of cellulose by the ruminant : a thesis presented in partial fulfilment of the requirements for the degree of Master of Agricultural Science in Animal Science at Massey University(Massey University, 1969) Kirk, Robin David1.Metabolism of Lipids by Ruminants Many workers have added fats, oils and fatty acids to the rations of sheep, beef cattle and dairy cows to investigate the effects of lipid on either one or more of the following; intake, digestibility end energy utilisation of rations, live weight gains, methane production, ammonia production, N retention, milk production, milk constituents, total VPA production and VFA molar proportions or the value of lipid as a source of energy. These factors will be discussed in subsequent sections of this review. Lipids which have been fed or infused into ruminants include coconut, cod liver, corn, cottonseed, linseed, palm kernel, peanut, soyabean, tung and whale oils, animal fats (lard, tallow and poultry fat) and long chain fatty acids (palmitic, stearic, oleic, linoleic and linolenic). Since the amount of lipid ingested by adult ruminants is substantial, the investigations into the effects of lipids are warranted. A cow consuming 45Kg. of pasture daily will ingest about 500g. of lipids and, under conditions of stall-feeding, pregnant and lactating animals may receive rations which provide up to 1.0Kg. of lipids daily (Garton, 1967).[FROM INTRODUCTION]Item On mathematical modelling of the self-heating of cellulosic materials : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Mathematics at Massey University, New Zealand(Massey University, 1991) Sisson, Robert AnthonyThis thesis considers mathematical modelling of self-heating of cellulosic materials, and in particular the effects of moisture on the heating characteristics. Following an introductory chapter containing a literature review, Chapter 2 presents some preliminary results and an industrial case study. The case study, which discusses a 'dry' body self-heating on a hot surface, investigates the following questions : (i) how hot can the surfa e get before ignition is likely? (ii) how well does the (slab like) boy approximate to an infinite slab? and (iii) how valid is the Frank Kamenetskii approximation for the source term? It is shown that the minimal stea dy state temperature profile is stable when the temperature of the hot surface is below a certain critical value, and bounds for the higher steady state profile are derived. Chapter 3 presents the thermo dynamic derivation of a reaction-diffusion model for the self-heating of a moist cellulosic body, including the effects of direct chemical oxi dation as well as those of a further exothermic hydrolysis reaction and the evaporation and condensation of water. The model contains three main variables: the temperature of the body, the liquid water concentration in the body, and the water vapour concentration in the body. Chapter 4 investigates the limiting case of the model equations as the thermal conductivity and diffusivity of the body be come large. In particular it is shown that, in this limiting case, the model can have at least twenty-five distinct bifurcation diagrams, compared with only two for the well known model without the effects of moisture content. In Chapter 5 the maximum principle and the methods of upper and lower solutions are used to derive existence, uniqueness and multiplicity results for the steady state solutions of the spatially distributed model. Finally, in Chapter 6, existence and uniqueness results for the time dependent spatially distributed model are derived.