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    Interaction of nitrogen fertilizer rates and plant population on growth, phenology, yield, and nutritional composition of Solanum scabrum
    (2023) Ndlovu, Sindi; van Jaarsveld, C.M. Mavengahama, S. and Ntuli, N.R.
    Solanum scabrum is a nutritious African leafy vegetable scarcely known in South Africa but consumed in other African countries. Very little is known about the agronomic requirements of this crop, including optimum fertilizer rates and plant population. This study focused on the effect of N fertilizer application and plant population on the growth, phenology, yield, and nutritional composition of S. scabrum. A field experiment was conducted at the University of Zululand farm in which S. scabrum was grown under 0, 100, 200, 300, and 400 kg ha-1 N (as limestone ammonium nitrate) and 100 000, 160 000, 220 000, and 280 000 plants per hectare in a randomised complete block design with three replications. Five randomly selected plants from the inner rows of each plot were marked and used to take measurements of vegetative traits (on plant height, leaf chlorophyll content, leaf area, and the number of leaves and branches) 35 days after transplanting. Phenological development of reproductive traits was recorded as duration (days after transplanting) to 50% flowering, fruit formation, and fruit maturity, using plants from the border rows. Plants from inner rows were harvested to measure marketable and non-marketable yield in fresh and dry mass (g). Ten centimetre long shoot tips were harvested for marketable yield at 35 and 56 days after transplanting. However, the non-marketable yield was determined from all aboveground parts harvested at 5 cm above soil level at the termination date. The same shoot tips were analysed for their N, P, K, Ca, Mg, Na, Al, Zn, Mn, Cu, and Fe content. Plant height and leaf area generally increased, but leaf chlorophyll content and the number of branches and leaves were inconsistent with an increase in N application. The effect of population size on plant height, the number of branches and leaves, leaf area, and leaf chlorophyll content were inconsistent. Nitrogen application of 300 and 400 kg ha-1 N and a low plant population (100 000 plants ha-1) increased the days to 50% flowering. Generally, applying N resulted in higher values for all yield parameters measured in this study. Further, yield parameters were higher at the lowest plant population (100 000 plants ha-1). Nitrogen application did not affect N, K, and Ca content, but reduced P content of the shoots. Its effect on the shoot Mg content was variable. Application of N had an inconsistent effect on the shoots’ Na, Zn, Cu, and Fe content. However, it reduced and increased the shoots’ Al and Mn content, respectively. Variation in plant population did not affect the macronutrients, whereas the application of N had an inconsistent effect on some micronutrients. The application of 300 kg ha– 1 was the optimum range for N fertilizer application, and 100 000 plants ha-1 was the optimum plant population relative to shoot fresh mass. This indicates potential for improving the crop through N fertilization, thereby contributing to food security and balanced diets in rural households in South Africa.
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    Effect of goat manure on growth, yield, and nutritional composition of Cucurbita argyrosperma
    (University of Zululand, 2023) Zondo, Nomfanelo; van Jaarsveld, C.M. Ntuli, N.R. and Mavengahama, S.
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    Evaluation and identification of fibro-lytic potential tannin-tolerant microbes from wild herbivores to improve goat browse utilization
    (University of Zululand, 2023) Msimango, Nokwethemba Nqobile Philile
    Livestock production in developing countries is constrained by insufficient feed quality to sustain high productivity particularly during dry seasons. During this period, ruminants switch their diet from mixed feeding to principally browsing drought-resistant trees and shrubs containing different types and concentrations of tannins. Consuming high tannin forages reduce nutrient digestibility but small amounts can be beneficial, especially in the presence of rumen bacteria that can tolerate tannins. The objectives of the study were to monitor microbial ecosystems from wild herbivores; manipulate, evaluate and identify tannin tolerant microbes; and create microbial ecosystems with higher fibrolytic potential to use browse species in goats. To achieve these objectives, a series of experiments were conducted. Experiment 1 investigated the effect of condensed tannins on the fibrolytic activity of an microbial ecosystem from goats (G), giraffes (GR), kudus (K), impalas (IM) and a consortia of animals [A1 (G+IM), A2 (G+KD), A3 (G+GR), A4 (GR+IM), A5 (GR+KD), A6 (IM+KD), A7 (G+GR+IM), A8 (G+GR+KD), A9 (G+IM+KD), A10 (GR+KD+IM), A11 (G+GR+KD+IM)]. Fresh faecal samples were collected and mixed with homogenization buffer for crude enzyme extraction. Crude enzyme extracts were precipitated with 60% ammonium sulphate followed by dialysis, and assayed for endocellulase, exocellulase and xylanase activities by incubating with arboxymethyl cellulose, microcrystalline cellulolse and xylan, respectively. An in vitro fermentation study was done by incubating strained faecal fluid with medium containing 1g of Vacchellia sieberiana at different concentrations of condensed tannins [control (feed without adjustment 5.34%), 8 and 10%]. Apparent degradability (APD), True degradability (TD), Neutral detergent fiber degradability (NDFd), Acid detergent fiber degradability (ADFd) and Microbial yield (MY) were measured. Supplementation of V. sieberiana with condensed tannins had significant effect on enzymes specific activities (endocellulase, exocellulase, xylanase) and fibre degradability. Supplemented group had lower enzyme activities, neutral detergent fiber (NDF), acid detergent fiber (ADF), apparent degradability (APD) and true degradability (TD). However, microbial consortia improved (P<0.05) goats’ fibrolytic enzyme activities and dry matter degradability. Therefore, at the end of the in vitro study, microbial consortia [A7 (G+GR+IM), A1 (IM+G), A9 (G+K+I) and A11 (G+GR+KD+IM)] were the most promising and effective microbial ecosystems to enhance goat fibrolytic activities and was thus selected for further studies. Experiments 2 and 3 isolated and identified tannin tolerant bacteria from faecal matter of goats (G), giraffes (GR), kudus (K), impalas (IM) and the best performing consortia [A= A7 (G+GR+IM), B= A1 (IM+G), C= A9 (G+K+IM) and D= A11 (G+GR+K+IM)] on goat fibrolytic activity. Thirteen tannin tolerant bacteria were isolated from the enrichment cultures of faecal microflora through serial dilutions and spread plate method in a medium containing condensed tannins as a sole carbon source and energy. The isolates were identified based on morphological, biochemical characteristics and 16S rDNA gene sequences. A total of 13 Gram-negative and Gram-positive tannin tolerant bacteria designated as G, GR2, A1, B2, D2, C1, GR1, D2, A2, B1, K, I and C2 were isolated and identified as members of the Gram-negative Escherichia sp. (6), Gram positive Enterococcus sp. (5) and Bacillus species (1). A new Gram positive (B1) strain that does have any similarity with reference strain in the NCBI nucleotide database was also identified. In Experiment 4, tannin-tolerant bacterial isolates were screened to produce endocellulase, exocellulase and xylanase enzymes on carboxymethyl cellulose (CMC), microcrystalline cellulose (MCC) and xylan (XY) agar plates, respectively, following the gram’s iodine staining procedure. Enzymes were extracted from each potential isolate and the enzyme activity assay was performed based on 3,5 dinitrosalicylic acid (DNS) method. Temperature, incubation time and pH were then optimised for maximum activity of exocellulase, endocellulase and xylanases. Out of 13 bacterial isolates, two strains (15%) were able to utilize CMC, MCC and XY, five strains (39%) were able to use CMC and XY and six strains (46 %) were not able to use any of these substrates. The optimum temperature for enzyme (cellulase and xylanase) activities was 40°C. However, optimal incubation period and pH varied among bacterial species. In conclusion, fibrolytic microbes were identified from wild ruminant systems and tested on a goat system. Improved fibrolytic activity on goats was confirmed and the study identified 13 tannin tolerant bacteria. The tannin tolerant fibrolytic microbes identified in this study may have evolved in response to the dietary and environmental pressure, especially of the wild systems, as the animals normally consume feed with high tannin concentrations in their natural habitat. Therefore, it is possible that the selective pressures imposed by these diets over time have led to the evolution of specialised microbial communities that are better suited to produce enzymes breakingdown fibrous plant material and extracting nutrients in the presence of tannins. Identifying tannin-tolerant fibrolytic microbes can be used to develop supplements that could help improve the digestive health and nutrient absorption of goats. Future research is needed for fuller understanding of the benefits of modifying domestic animals’ microbiome with tannin-tolerant bacteria from the wild. OKUHUNYUSHWE NGOLIMI LWESIZULU Isifinyezo Ukukhiqizwa kwemfuyo emazweni asathuthuka kuvinjelwa izinga lokudla okunganele ukuze kugcinwe umkhiqizo ophezulu ikakhulukazi ngesikhathi sesomiso. Ngalesi sikhathi, izilwane ezelusayo zishintsha ukudla kwazo zisuke ekudleni okuxubile ziye ekuphequluleni izihlahla ezimelana nesomiso kanye nezihlahlana eziqukethe izinhlobo ezahlukene kanye nokugcwala kwama-tannins. Ukudla ukudla okune-tannin eliphezulu kunciphisa ukugayeka kokudla okunomsoco kodwa amanani aphansi angasiza, ikakhulukazi uma kukhona ama-microorganisms esiswini angamelana namatannin. Izinjongo zocwaningo bekuwukuqapha imvelo ye-microbial evela ezilwaneni ezidla uhlaza zasendle; phatha, uhlole futhi uhlonze amabhaktheriya abekezelela i-tannin; futhi adale ama-microbial ecosystem anamandla aphezulu efibrolytic okusebenzisa izinhlobo zokuphequlula ezimbuzini. Ukufeza lezi zinhloso, uchungechunge lwezilingo lwenziwa. Ukuhlolwa koku-1 kuphenye umthelela wama-tannin ajiyile emsebenzini wefibrolytic we-microbial ecosystem evela ezimbuzini (G), izindlulamithi (GR), i-kudus (K), i-impalas (IM) kanye nenhlanganisela yezilwane [A1 (G+IM), A2 (G+KD), A3 (G+GR), A4 (GR+IM), A5 (GR+KD), A6 (IM+KD), A7 (G+GR+IM), A8 (G+GR+KD ), A9 (G+IM+KD), A10 (GR+KD+IM), A11 (G+GR+KD+IM)]. Amasampula endle amasha aqoqwa futhi axutshwa ne-homogenization buffer ukuze kukhishwe i-enzyme engahluziwe. Ukukhishwa kwe-enzyme engahluziwe kwehliswe nge-60% yeammonium sulphate elandelwa yi-dialysis, futhi yahlolwa imisebenzi yeendocellulase, i-exocellulase kanye ne-xylanase ngokufukamela nge-carboxymethyl cellulose, i-microcrystalline cellulolse ne-xylan, ngokulandelana. Ucwaningo lokuvutshelwa kwe-in vitro lwenziwa ngokufukamela uketshezi lwendle olucindezelwe phakathi nendawo equkethe i-1g ye-Vacchellia sieberiana ekugxilweni okuhlukene kwama-tannins ajiyile [ukulawula (ukuphakela ngaphandle kokulungisa 5.34%), 8 kanye no-10%]. Ukuwohloka okubonakalayo (i-APD), ukuwohloka kweqiniso (TD), ukuwohloka kwefayibha yokuhlanza engathathi hlangothi (NDFd), ukuwohloka kwefayibha yokuhlanza i-Acid (ADFd) kanye nesivuno seMicrobial (MY) kukalwa. Ukwengezwa kwe-V. sieberiana ngama-tannins ajikisiwe kube nomthelela omkhulu emisebenzini ethile yama-enzyme (i-endocellulase, i-exocellulase, i-xylanase) kanye nokuwohloka kwe-fiber. Iqembu elengeziwe lalinemisebenzi ephansi yama-enzyme, i-neutral detergent fiber (NDF), i-acid detergent fiber (ADF), i-apparent degradability (APD) kanye nokonakala kweqiniso (TD). Kodwa-ke, i-microbial consortia yenza ngcono (P<0.05) imisebenzi ye-enzyme ye-fibrolytic yezimbuzi kanye nokuwohloka kwento eyomile. Ngakho-ke, ekupheleni kocwaningo lwe-in vitro, i-microbial consortia [A7 (G+GR+IM), A1 (IM+G), A9 (G+K+I) kanye ne-A11 (G+GR+KD+IM)] kwakuyizinto eziphilayo ezithembisayo nezisebenza kahle kakhulu ze-microbial ecosystem ukuze kuthuthukiswe imisebenzi ye-goat fibrolytic futhi ngaleyo ndlela yakhethelwa izifundo eziqhubekayo. Ukuhlola 2 kanye no-3 amagciwane angakwazi ukumelana ne-tannin ahlukanisiwe avela ezimbuzini (G), izindlulamithi (GR), i-kudus (K), i-impalas (IM) kanye ne-consortia eyenza kahle kakhulu [A= A7 (G+GR+IM), B= A1 (IM+G), C= A9 (G+K+IM) kanye no-D= A11 (G+GR+K+IM)] emisebenzini ye-fibrolytic yembuzi. Amagciwane ayishumi nantathu abekezelela i-tannin ahlukaniswa kumasiko okunothisa we-microflora yendle ngokusebenzisa ukuhlanjululwa okulandelanayo kanye nendlela yokusabalalisa ipuleti endaweni equkethe ama-tannins ajiyile njengomthombo wekhabhoni kanye namandla. Ama-isolate akhonjwe ngokusekelwe ku-morphological, izici ze-biochemical kanye nokulandelana kofuzo kwe-16S rDNA. Isamba samagciwane angu-13 abekezelela i-tannin e-Gram-negative kanye ne-Gram-positive aqokwe njenge-G, GR2, A1, B2, D2, C1, GR1, D2, A2, B1, K, I kanye ne-C2 ahlukaniswa futhi akhonjwa njengamalungu e-Gram. -negative Escherichia sp. (6), i-Gram positive Enterococcus sp. (5) kanye nezinhlobo ze-Bacillus (1). Kuphinde kwahlonzwa uhlobo olusha lwe-Gram positive (B1) olunokufana nereferensi kusizindalwazi se-nucleotide ye-NCBI. Esivivinyweni sesi-4, ama-bacterial isolate abekezelela i-tannin ahlolwa ukuze kukhiqizwe ama-endocellulase, i-exocellulase ne-xylanase enzyme ku-carboxymethyl cellulose (CMC), i-microcrystalline cellulose (MCC) kanye namapuleti e-agar e-xylan (XY), ngokulandelana, kulandelwa inqubo yokungcolisa i-iodine yegremu. Ama-Enzyme akhishwe ku-isolate ngayinye engaba khona futhi ukuhlolwa komsebenzi weenzyme kwenziwa ngokusekelwe ku-3,5 ye-dinitro-salicylic acid (DNS) indlela. Izinga lokushisa, isikhathi sokufukamela kanye ne-pH kwabe sekulungiselelwa umsebenzi omkhulu we-exocellulase, endocellulase kanye ne-xylanases. Kwezihlukanisiwe zamabhaktheriya eziyi-13, izinhlobo ezimbili (15%) zikwazile ukusebenzisa i-CMC, i-MCC ne-XY, izinhlobo ezinhlanu (39%) zikwazile ukusebenzisa i-CMC ne-XY kanye nezinhlobo eziyisithupha (46%) azikwazanga ukusebenzisa noma iyiphi yalezi. amasubstrates. Izinga lokushisa elilungile lemisebenzi ye-enzyme (i-cellulase nexylanase) lalingu-40°C. Kodwa-ke, isikhathi esifanele sokufukamela kanye ne-pH yahlukahluka phakathi kwezinhlobo zamabhaktheriya. Isiphetho, ama-microbes e-fibrolytic ahlonzwa ezinhlelweni ze-ruminant zasendle futhi ahlolwe ohlelweni lwezimbuzi. Umsebenzi owenziwe ngcono wefibrolytic ezimbuzini waqinisekiswa futhi ucwaningo lwathola amagciwane ayi-13 abekezelela i-tannin. Amagciwane e-fibrolytic abekezelela i-tannin ahlonzwe kulolu cwaningo kungenzeka ukuthi avela ngenxa yengcindezi yokudla kanye nemvelo, ikakhulukazi yezinhlelo zasendle, njengoba izilwane zivame ukudla ukudla kunetannin ephezulu endaweni yazo yemvelo. Ngakho-ke, kungenzeka ukuthi izingcindezi ezikhethiwe ezibekwe yilokhu kudla ngokuhamba kwesikhathi ziye zaholela ekuguqukeni kwemiphakathi ekhethekile yamagciwane afaneleka kangcono ukukhiqiza ama-enzyme aphula impahla yezitshalo ze-fibrous kanye nokukhipha imisoco phambi kwama-tannins. Ukuhlonza amagciwane e-fibrolytic abekezelela itannin kungasetshenziswa ukwenza izithasiselo ezingasiza ukuthuthukisa impilo yokugaya ukudla kanye nokumunca izakhamzimba zezimbuzi. Ucwaningo esikhathi esizayo luyadingeka ukuze kuqondwe ngokugcwele izinzuzo zokushintsha imicrobiome yezilwane ezifuywayo ngamagciwane abekezelela ama-tannin avela endle.
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    Method development and proteomic profiling of boar seminal plasma using mass spectrometry-based workflows
    (University of Zululand, 2023) Mokwena, Pateswana Wilson; Lehloenya, K. C. Stoychev, S. Ramukhithi, F. V. R.
    Artificial insemination is an important technology in the swine industry; it is of great significance in the preservation and improvement of elite breeds. Conventional methods used in assessing semen lack precision, and the use of low fertile boars in breeding systems is prominent. Using mass spectrometry in fertility studies has gained momentum in the race for new markers of fertility and semen cryopreservation. Therefore, the aim of this study was to develop and optimise a mass spectrometry-based proteomic method suitable for profiling boar seminal plasma. To accomplish this aim, gel-based and in-solution methods were evaluated for depth-of-coverage, reproducibility and throughput. For the gel-based method, one-dimensional sodium dodecyl sulphate (SDS)-polyacrylamide gel electrophoresis was coupled to in-gel digestion and liquid chromatography-tandem mass spectrometry (LC-MS/MS). For the in-solution methods, acetone precipitation was evaluated by either SDS or urea re-solubilisation, followed by semi-automated on-bead protein capture, clean-up, digestion and LC-MS/MS analysis. The gel-based method data were acquired through data-dependant acquisition and protein identifications were generated through a database search (ParagonTM Algorithm of the ProteinPilotTM Software, v5.0.2). The in-solution data were obtained via the sequential window acquisition of all theoretical mass-data independent acquisition method and protein identification; relative protein quantification was performed using Spectronaut® Software v16. Regarding in-solution analysis, the precipitated and non-precipitated methods performed similarly in terms of the depth of coverage (number of peptides and proteins detected) and reproducibility. Hence, direct analysis of seminal plasma without up-front precipitation was possible. The gel-based method did not improve the identification of peptides and proteins compared with the in-solution workflow. Novel peptide level fractionation was incorporated into the in-solution method to increase protein coverage during a pilot study of eight boars from three breeds (two Large White, three each Kolbroek and Windsnyer). Five hundred and eighty-seven proteins from 233 protein groups were identified across all runs. Thirty-nine proteins were differentially expressed between the Kolbroek and Windsnyer boars. In gene ontology terms, most differentially expressed proteins showed catalytic functions; a very small proportion were identified as directly involved in reproductive functions.
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    Synthesis and Fabrication of Alpha Phase Iron Oxide (α-Fe2O3) Nanostructured doped with Ruthenium for Highly Sensitive and Selective Flammable and Toxic Gas Sensor
    (2022) Cebekhulu, Ntokozo God-Knowledge
    The increase in the number of manufacturing industries in recent times had both positive and negative impacts on our environment and human health. The use of heavy-duty machines in manufacturing industries causes the release of flammable and hazardous gases, which affect human health, into the atmosphere. Many research efforts have been focused on detecting and monitoring these gases using metal oxide semiconductor materials. This study investigates the gas sensing performance of ruthenium-doped alpha iron oxide towards flammable and hazardous gases. The chemical precipitation method synthesised the alpha iron oxide doped with a different weight percentage of ruthenium. The samples underwent some characterisation techniques, such as X-ray diffractometry, thermogravimetric analysis, x-ray photoelectron spectroscopy, Brunauer-emmett-teller surface area analysis, scanning electron microscopy, and high-resolution transmission electron microscopy, to study certain properties of the material. The sensors were fabricated by using the drop casting method, and the sensors were tested for gas sensing performance at 225 ⁰C operating temperature, towards liquefied petroleum gas (LPG), ethanol, propanol, ammonium (NH3), and hydrogen sulphide (H2S). The pure sample alpha iron oxide (α Fe2O3) was more sensitive to the target gases with the response being 26.01 towards the ammonia gas. The selectivity shift towards LPG while the response decreases upon the addition of different weight percentage of the ruthenium to alpha iron oxide ruthenium was found to be unsuitable as a dopant material in alpha iron oxide for gas sensing applications.