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Effect of growth phase on the Fatty Acid Compositions of Four Species of Marine Diatoms

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Journal of Ocean University of China 2005年第2期4卷 157-162页

作者： LIANGYing MAIKangsen TheKeyLaboratoryofMariculture MinistryofEducationOceanUniversityofChinaQingdao266003P.R.China

The fatty acid compositions of four species of marine diatoms (Chaetoceros gracilis MACC/B13, Cylindrotheca fusiformis MACC/B211, Phaeodactylum tricornutum MACC/B221 and Nitzschia closterium MACC/B222), cultivated at 22 ℃± 1 ℃ with the salinity of 28 in f/2 medium and harvested in the exponential growth phase, the early stationary phase and the late stationary phase, were determined. The results showed that growth phase has significant effect on most fatty acid contents in the four species of marine diatoms. The proportions of 16:0 and 16:1n-7 fatty acids increased while those of 16:3n-4 and eicosapentaenoic acid (EPA) decreased with increasing culture age in all species studied. The subtotal of saturated fatty acids (SFA) increased with the increasing culture age in all species with the exception of B13. The subtotal of monounsaturated fatty acids (MUFA) increased while that of polyunsaturated fatty acids (PUFA) decreased with culture age in the four species of marine diatoms. MUFA reached their lowest value in the exponential growth phase, whereas PUFA reached their highest value in the same phase.

关键词： Chaetoceros gracilis Cylindrotheca fusiformis Phaeodactylum tricornutum Nitzschia closterium growth phase fatty acid

Dynamic Proteome Changes of Shigella flexneri 2a During Transition from Exponential growth to Stationary phase

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Genomics, Proteomics & Bioinformatics 2007年第2期5卷 111-120页

作者： Li Zhu Xian-Kai Liu Ge Zhao Yi-Dan Zhi Xin Bu Tian-Yi Ying Er-Ling Feng Jie Wang Xue-Min Zhang Pei-Tang Huang Heng-Liang Wang State Key Laboratory of Pathogen and Biosecurity Beijing Institute of Biotechnology Beijing 100071 China National Center of Biomedical Analysis Beijing 100850 China

Shigella flexneri is an infectious pathogen that causes dysentery to human, which remains a serious threat to public health, particularly in developing countries. In this study, the global protein expression patterns of S. flexneri during transition from exponential growth to stationary phase in vitro were analyzed by using 2-D PAGE combined with MALDI-TOF MS. In a time-course experiment with five time points, the relative abundance of 49 protein spots varied significantly. Interestingly, a putative outer membrane protein YciD （OmpW） was almost not detected in the exponential growth phase but became one of the most abundant proteins in the whole stationary-phase proteome. Some proteins regulated by the global regulator FNR were also significantly induced （such as AnsB, AspA, FrdAB, and KatG） or repressed （such as AceEF, OmpX, SodA, and SucAB） during the growth phase transition. These proteins may be the key effectors of the bacterial cell cycle or play important roles in the cellular maintenance and stress responses. Our expression profile data provide valuable information for the study of bacterial physiology and form the basis for future proteomic analyses of this pathogen.

关键词： Shigella flexneri proteomics growth phase

Variation in Rubisco and other photosynthetic parameters in the life cycle of Haematococcus pluvialis

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Chinese Journal of Oceanology and Limnology 2012年第1期30卷 136-145页

作者： CHEN Zhangfan WANG Guangce NIU Jianfeng Key Laboratory of Experimental Marine Biology Institute of OceanologyChinese Academy of SciencesQingdao 266071 China Graduate University of Chinese Academy of Sciences Beijing 100049China

Cells of Haematococcus pluvialis Flot. et Will were collected in four different growth phases. We quantified the initial and total enzyme activity of ribulose-1,5-bisphosphate carboxylase （Rubiseo） in crude extracts, and the relative expression of large-subunit ribulose-1,5-bisphosphate caboxylase / oxygenase （rbcL） mRNA. We measured the ratio of photosynthetic rate to respiration rate （P/R）, maximal effective quantum yield of photosystem II （Fv/Fm）, electron transport rate （ETR）, actual photochemical efficiency of PSI1 in the light （ФPSII）, and non-photochemical quenching （NPQ）. Green vegetative cells were found to be in the most active state, with a relatively higher P/R ratio. These cells also displayed the lowest NPQ and the highest Fv/Fm, ETR, and ФPSII, indicating the most effective PSII. However, both Rubisco activity and rbcL mRNA expression were the lowest measured. In orange resting cysts with relatively lower P/R and NPQ, Rubisco activity and rbcL expression reached a peak, while Fv/Fm, ETR, and ФPSII were the lowest measured. Taking into account the methods of astaxanthin induction used in industry, we suggest that Rubisco may participate in astaxanthin accumulation in H. pluvialis. A continuous and sufficient supply of a carbon source such as CO2 may therefore aid the large scale production of astaxanthin.

关键词： Haematococcus pluvialis Rubisco astaxanthin life cycle growth phase

A Combined Approach of Principal Component Analysis and Support Vector Machine for Early Development phase Modeling of Ohrid Trout(Salmo Letnica)

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Computer Modeling in Engineering & Sciences 2021年第3期126卷 991-1009页

作者： Sunil Kr.Jha Ivan Uzunov Xiaorui Zhang School of Computer and Software Nanjing University of Information Science and TechnologyNanjing210044China Faculty of Computer Science and Engineering University of Information Science and TechnologyOhrid6000Republic of Macedonia

Ohrid trout(Salamo letnica)is an endemic species of fish found in Lake Ohrid in the Former Yugoslav Republic of Macedonia(FYROM).The growth of Ohrid trout was examined in a controlled environment for a certain period,thereafter released into the lake to grow their natural *** external features of the fish were measured regularly during the cultivation period in the laboratory to monitor their *** data mining methods-based computational model can be used for fast,accurate,reliable,automatic,and improved growth monitoring procedures and classification of Ohrid *** this motivation,a combined approach of principal component analysis(PCA)and support vectormachine(SVM)has been implemented for the visual discrimination and quantitative classification of Ohrid trout of the experimental and natural breeding and their growth *** PCA results in better discrimination of breeding categories of Ohrid trout at different development phases while the maximum classification accuracy of 98.33% was achieved using the combination of PCA and *** classification performance of the combination of PCA and SVM has been compared to combinations of PCA and other classification methods(multilayer perceptron,naive Bayes,randomcommittee,decision stump,random forest,and random tree).Besides,the classification accuracy of multilayer perceptron using the original features has been studied.

关键词： Salamo letnica growth phase modeling PCA SVM

Cross-protective effect of acid adaptation on ethanol tolerance in Salmonella Enteritidis

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Food Science and Human Wellness 2023年第4期12卷 1402-1407页

作者： Shoukui He Beining Ye Zengfeng Zhang Yan Cui Siyun Wang Xianming Shi MOST-USDA Joint Research Center for Food Safety School of Agriculture and BiologyState Key Lab of Microbial MetabolismShanghai Jiao Tong UniversityShanghai 200240China Food Nutrition and HealthFaculty of Land and Food SystemsThe University of British ColumbiaVancouver BC V6T 1Z4Canada

Cross protection can undermine the effectiveness of control measures on foodborne pathogens,and therefore brings major implications for food *** this work,the capacity of Salmonella Enteritidis to mount ethanol tolerance following acid adaptation was characterized by analysis of cell viability and cell membrane *** was observed that preadaptation to pH 4.5 significantly(Pphase cells to ethanol;in contrast,stationary-phase cells displayed reduced ethanol tolerance after acid ***,acid adaptation did not cause cell leakage and morphological change in both log-phase and stationary-phase *** acid analysis further revealed that the amount of C_(14:0),C_(17:0 cyclo) and C_(19:0 cyclo) fatty acids was increased,while that of C_(16:1ω7c) and C_(18:1ω7c) fatty acids was decreased,respectively,in response to acid adaptation,regardless of bacterial growth ***,acid adaptation significantly(Pphase cells,but this effect did not occur in stationary-phase ***,exogenous addition of C_(16:0) fatty acid to stationary-phase acid-adapted cultures was able to enhance bacterial ethanol *** together,C_(16:0) fatty acid is involved in the growth-phase-dependent protective effect of acid adaptation on ethanol tolerance in ***.

关键词： Salmonella Enteritidis Acid adaptation Ethanol tolerance growth phase Fatty acid

Cellular growth Dynamics Affects Allelopathic Activity in Coffee Cell Culture

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American Journal of Plant Sciences 2023年第8期14卷 857-868页

作者： Muchamad Imam Asrori Shinjiro Ogita Graduate School of Comprehensive Scientific Research Prefectural University of Hiroshima Hiroshima Japan

Cellular growth dynamics and allelopathic activity in coffee cell cultures were examined as follows: First, we compared allelopathic activity of seven woody plant calli, Coffea canephora, Derris indica, Ficus carica L., Juniperus conferta, Prunus persica, Punica granatum, and Sonneratia ovata, using a modified “sandwich method bioassay” and found that coffee callus showed the strongest growth inhibition to lettuce seedling nearly 90% of hypocotyl and 96% of root. This coffee callus actively proliferated, with a 21-fold increase during five weeks of subculture, with a growth curve comprising two typical phases: a lag phase of 0 - 2 weeks of culture and an exponential phase of 3 - 5 weeks of culture. Allelopathic activity varied depending on the growth phase of the coffee callus. The strongest allelopathic activity was detected in 1 - 2-week-old callus showing nearly 100% inhibitory effect on lettuce seedling growth. As the allelopathic activity of coffee calli is extremely high, beyond the natural level in coffee leaves and green beans, we focused on analyzing the allelopathic activity of its aqueous extracts using high-performance liquid chromatography. Several prominent peaks, including two reference alkaloids, theobromine and caffeine, which are known allelochemicals in coffee plants, and three distinct unknown peaks were identified at 270 nm in coffee calli during the lag phase (1 - 2 weeks of culture). The higher value of the total phenolic content in the lag phase also suggested a key biosynthetic pathway in relation to the allelopathic activity of coffee callus will be activated in the lag phase.

关键词： Allelopathic Activity Coffea canephora Callus growth phase Sandwich Method Bioassay

Observations of successive substorm onsets

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Observations of successive substorm onsets