Asexual proliferative seedling technology for Sargassum fusiforme constructed using tissue culture method

The traditional method of sexual reproduction in Sargassum fusiforme can lead to difficulties in maintaining the stable inheritance of superior traits. However, technology for asexual proliferation of seedlings in seaweed tissue culture is not well-developed. Therefore, we established a tissue culture method to study, the effects of different parts of S. fusiforme, uniconazole (UIZ) concentrations, and culture methods on the regeneration of tissue-derived juveniles of S. fusiforme. The results showed that the optimal culture conditions were solid medium with modified Provassoli’s enriched seawater containing 3 μM UIZ for at least 17 days followed by transfer to liquid medium to induce rapid cell proliferation. These optimal conditions resulted in a callus-like/adventitious bud induction rate of 100%, callus-like/adventitious bud number per explant of 27.43 ± 4.57, and relative growth rate of 3.05 ± 0.27. The best plant parts for tissue culture were the filamentous holdfasts followed by the stem tip. In addition, UIZ treatment increased photosynthesis, resulting in soluble sugar and soluble protein contents of 30.47 mg·g-1 and 1.39 mg·g-1 of in the regenerated juveniles. Based on our results, S. fusiforme can be cultured using a tissue culture technique in which UIZ is added to a solid medium, followed by culture in liquid medium for proliferation. Sargassum fusiforme juveniles obtained using this technique can be cultured continuously until the next culture season and grow normally, providing a technical reference for indoor preservation and expansion of algal species

Fresh living Arthrospira as dietary supplements: Current status and challenges

© 2019 Elsevier Ltd. This manuscript version is made available under the CC-BY-NC-ND 4.0 license: http://creativecommons.org/licenses/by-nc-nd/4.0/ This author accepted manuscript is made available following 12 month embargo from date of publication (April 2019) in accordance with the publisher’s archiving policyBackground Arthrospira (Spirulina) spp. has long been consumed as a dietary supplement that provides rich natural nutrients consisting of 60–70% proteins including essential amino acids, vitamins, and some minerals. The currently available Spirulina products in the market are mainly hot and spray-dried and their nutritional values are significantly compromised due to degradation of the heat-sensitive bioactive components. Scope and approach This commentary provides a critical view on the differences in main nutritional composition between dried and fresh living Arthrospira. In addition, the current R&D advances in the development of fresh living Arthrospira as a dietary supplement including the cultivation system, preservation and storage, product development, nutritional and functional properties and food safety were critically discussed. Key findings and conclusions Fresh living Arthrospira can better maintain their nutritional, functional, and health values, and therefore could be developed for a new range of Arthrospira derived products. However, the cultivation system that could ensure the food safety and long-term storage technologies to preserve the cell viability in different product formulations are still under development for expanding the commercial applications

Advances, Synergy, and Perspectives of Machine Learning and Biobased Polymers for Energy, Fuels, and Biochemicals for a Sustainable Future

This review illuminates the pivotal synergy between machine learning (ML) and biopolymers, spotlighting their combined potential to reshape sustainable energy, fuels, and biochemicals. Biobased polymers, derived from renewable sources, have garnered attention for their roles in sustainable energy and fuel sectors. These polymers, when integrated with ML techniques, exhibit enhanced functionalities, optimizing renewable energy systems, storage, and conversion. Detailed case studies reveal the potential of biobased polymers in energy applications and the fuel industry, further showcasing how ML bolsters fuel efficiency and innovation. The intersection of biobased polymers and ML also marks advancements in biochemical production, emphasizing innovations in drug delivery and medical device development. This review underscores the imperative of harnessing the convergence of ML and biobased polymers for future global sustainability endeavors in energy, fuels, and biochemicals. The collective evidence presented asserts the immense promise this union holds for steering a sustainable and innovative trajectory

Dynamics of a harvested cyanobacteria-fish model with modified Holling type Ⅳ functional response

In this paper, considering the aggregation effect and Allee effect of cyanobacteria populations and the harvesting of both cyanobacteria and fish by human beings, a new cyanobacteria-fish model with two harvesting terms and a modified Holling type Ⅳ functional response function is proposed. The main purpose of this paper is to further elucidate the influence of harvesting terms on the dynamic behavior of a cyanobacteria-fish model. Critical conditions for the existence and stability of several interior equilibria are given. The economic equilibria and the maximum sustainable total yield problem are also studied. The model exhibits several bifurcations, such as transcritical bifurcation, saddle-node bifurcation, Hopf bifurcation and Bogdanov-Takens bifurcation. It is concluded from a biological perspective that the survival mode of cyanobacteria and fish can be determined by the harvesting terms. Finally, concrete examples of our model are given through numerical simulations to verify and enrich the theoretical results

Bifurcation analysis of Leslie-Gower predator-prey system with harvesting and fear effect

In the paper, a Leslie-Gower predator-prey system with harvesting and fear effect is considered. The existence and stability of all possible equilibrium points are analyzed. The bifurcation dynamic behavior at key equilibrium points is investigated to explore the intrinsic driving mechanisms of population interaction modes. It is shown that the system undergoes various bifurcations, including transcritical, saddle-node, Hopf and Bogdanov-Takens bifurcations. The numerical simulation results show that harvesting and fear effect can seriously affect the dynamic evolution trend and coexistence mode. Furthermore, it is particularly worth pointing out that harvesting not only drives changes in population coexistence mode, but also has a certain degree delay. Finally, it is anticipated that these research results will be beneficial for the vigorous development of predator-prey system

Proizvodnja arahidonske kiseline iz Mortierella alpina I49 i N18

Arachidonic acid (AA), an essential fatty acid in human body, fermented by Mortierella alpina I49-N18 was investigated in a shake-flask, and a 50-ton fermentor. In order to optimize the culture conditions, the effects of temperature, initial pH, culture time, carbon and nitrogen sources were studied. Furthermore, the way of adding sugar during fermentation was evaluated in a 50-ton fermentor. Under the optimum culture conditions, arachidonic acid produced in shake-flask and 50-ton fermentor was 4.55 and 5.11 g/L media, respectively. It was shown that the highest percentage of AA in lipids in shake-flask and 50-ton fermentor reached 70.20 and 53.01 %, respectively. Gas chromatography/mass spectrometry tests showed that the oil contained 80 % of polyunsaturated fatty acids such as arachidonic acid, γ-linolenic acid, and linoleic acid.Istraživana je fermentacija Mortierella alpina I49 i N18 u tikvicama na tresilici i u 50-tonskom fermentoru za dobivanje arahidonske kiseline, esencijalne masne kiseline u čovjeka. Da bi se postigli najpovoljniji uvjeti uzgoja, ispitan je utjecaj temperature, početnog pH, trajanje uzgoja, izvori ugljika i dušika. Nadalje, ispitan je način dodavanja šećera tijekom uzgoja u 50-tonskom fermentoru. Pod optimalnim uvjetima uzgoja na tresilici i u 50-tonskom fermentoru dobiveno je 4,55 odnosno 5,11 g arahidonske kiseline/L podloge. Najveći je postotak arahidonske kiseline u lipidima na tresilici i u 50-tonskom fermentoru iznosio 70,20 odnosno 53,01 %. Plinskom kromatografijom/masenom spektrometrijom utvrđeno je da ulje sadrži 80 % polinezasićenih kiselina kao što su arahidonska, γ-linolenska i linoleinska kiselina

Seaweed (Porphyra) cultivation enhances production of autochthonous refractory dissolved organic matter in coastal ecosystems

Seaweed cultivation contributes to coastal carbon sequestration making it a compelling strategy to mitigate global climate change. Porphyra (commonly known as nori) is an economically important seaweed known to have high release rates for biogenic dissolved and particulate organic matter (DOM and POM). However, the impact of Porphyra cultivation on coastal organic matter dynamics remains unclear. To fill this knowledge gap, we conducted investigations examining the quantity and optical properties of DOM and POM, microbial community structures and relevant environmental factors along a continuum from a subtropical river through its adjacent coastal Porphyra cultivation zone during the cultivation and non-cultivation periods. Dissolved organic carbon (DOC) concentration was significantly elevated during the cultivation versus non-cultivation period, while particulate organic carbon (POC) concentration decreased, thereby resulting in a higher DOC/POC ratio in the water column. Endmember mixing analysis further suggested that autochthonous organic matter dominated in the coastal cultivation zone during both periods, with limited inputs of terrestrial organic carbon. Redundancy analysis revealed that more microbial modules mediated organic matter transformations during the cultivation period, leading to a 169% higher estuarine addition of microbially-sourced humic-like C3 compared to the non-cultivation period. Our findings demonstrate that Porphyra cultivation enhanced coastal carbon sequestration by promoting the autochthonous production and transformation of refractory DOM, which has important implications for the sustainable management and development of coastal blue carbon strategies

Developmental neurotoxicity of an anatoxin-a-producing cyanobacteria (Aphanizomenon gracile) lysate to zebrafish (Danio rerio)

Harmful cyanobacterial blooms occur frequently worldwide with serious environmental impacts. Many detrimental cyanobacteria are well known for their potential to synthesize various cyanotoxins, posing significant threats to aquatic ecosystems and public health worldwide. While most studies focus on the toxicological impacts of microcystins and its main producer Microcystis aeruginosa, the ecotoxic effects of anatoxin-a and anatoxin-a-producing cyanobacteria are not fully understood. This study investigated the response of zebrafish (Danio rerio) to a ruptured cell solution (RCS) of a planktonic anatoxin-a-producing Aphanizomenon gracile. The RCS exposure negatively affected the hatching of zebrafish embryos, and promoted malformation. Furthermore, RCS treatment also disrupted neurobehaviors, and induced severe oxidative stress. In addition, the RCS inhibited the activity of acetylcholinesterase, and dysregulated the expression of several genes related to neuron-development and activated apoptosis in zebrafish. These results suggest that blooms of anatoxin-a-producing Aphanizomenon gracile will have neurotoxic effects on aquatic animals, and could impact human health. They help to further understand the potential neurotoxicity of harmful cyanobacteria, and highlight the need for further studies and risk assessments of the ecological impacts of harmful cyanobacterial blooms in freshwater ecosystems