Enrichment of Hydrogen Oxidizing Bacteria from High Temperature and Salinity Environments

There is an urgent need for sustainable protein supply routes with low environmental footprint. Recently, the use of hydrogen oxidizing bacteria (HOB) as a platform for high quality microbial protein (MP) production has regained interest. This study aims to investigate the added value of using conditions such as salt and temperature to steer HOB communities to lower diversities, while maintaining a high protein content and a high quality amino acid profile. Pressure drop and hydrogen consumption were measured for 56 days to evaluate autotrophy of a total of six communities in serum flasks. Of the six communities, four were enriched under saline (0.0, 0.25, 0.5 and 1.0 mol NaCl l−1) and two under thermophilic conditions (65°C). Five communities enriched for HOB were subsequently cultivated in continuously stirred reactors under the same conditions to evaluate their potential as microbial protein producers. The protein percentages ranged from 41 to 80%. The highest protein content was obtained for the thermophilic enrichments. Amino acid profiles were comparable to protein sources commonly used for feed purposes. Members of the genus Achromobacter were found to dominate the saline enrichments while members of the genus Hydrogenibacillus were found to dominate the thermophilic enrichments. Here we show that enriching for HOB while steering the community toward low diversity and maintaining a high quality protein content can be successfully achieved, both in saline and thermophilic conditions. IMPORTANCE Alternative feed and food supply chains are required to decrease water and land use. HOB offer a promising substitute for traditional agricultural practice to produce microbial protein (MP) from residual materials and renewable energy. To safeguard product stability, the composition of the HOB community should be controlled. Defining strategies to maintain the stability of the communities is therefore key for optimization purposes. In this study, we use salt and temperature as independent conditions to stabilize the composition of the HOB communities. Based on the results presented, we conclude that HOB communities can be steered to have low diversity using the presented conditions while producing a desirable protein content with a valuable amino acid profile.

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From Biogas and Hydrogen to Microbial Protein Through Co-Cultivation of Methane and Hydrogen Oxidizing Bacteria

Frontiers in Bioengineering and Biotechnology ◽

10.3389/fbioe.2021.733753 ◽

2021 ◽

Vol 9 ◽

Author(s):

Frederiek-Maarten Kerckhof ◽

Myrsini Sakarika ◽

Marie Van Giel ◽

Maarten Muys ◽

Pieter Vermeir ◽

...

Keyword(s):

Amino Acid ◽

Essential Amino Acid ◽

Protein Concentration ◽

Synergistic Effects ◽

Amino Acid Content ◽

Essential Amino Acids ◽

Amino Acid Profile ◽

Microbial Protein ◽

Waste Streams ◽

Hydrogen Oxidizing Bacteria

Increasing efforts are directed towards the development of sustainable alternative protein sources among which microbial protein (MP) is one of the most promising. Especially when waste streams are used as substrates, the case for MP could become environmentally favorable. The risks of using organic waste streams for MP production–the presence of pathogens or toxicants–can be mitigated by their anaerobic digestion and subsequent aerobic assimilation of the (filter-sterilized) biogas. Even though methane and hydrogen oxidizing bacteria (MOB and HOB) have been intensively studied for MP production, the potential benefits of their co-cultivation remain elusive. Here, we isolated a diverse group of novel HOB (that were capable of autotrophic metabolism), and co-cultured them with a defined set of MOB, which could be grown on a mixture of biogas and H2/O2. The combination of MOB and HOB, apart from the CH4 and CO2 contained in biogas, can also enable the valorization of the CO2 that results from the oxidation of methane by the MOB. Different MOB and HOB combinations were grown in serum vials to identify the best-performing ones. We observed synergistic effects on growth for several combinations, and in all combinations a co-culture consisting out of both HOB and MOB could be maintained during five days of cultivation. Relative to the axenic growth, five out of the ten co-cultures exhibited 1.1–3.8 times higher protein concentration and two combinations presented 2.4–6.1 times higher essential amino acid content. The MP produced in this study generally contained lower amounts of the essential amino acids histidine, lysine and threonine, compared to tofu and fishmeal. The most promising combination in terms of protein concentration and essential amino acid profile was Methyloparacoccus murrelli LMG 27482 with Cupriavidus necator LMG 1201. Microbial protein from M. murrelli and C. necator requires 27–67% less quantity than chicken, whole egg and tofu, while it only requires 15% more quantity than the amino acid-dense soybean to cover the needs of an average adult. In conclusion, while limitations still exist, the co-cultivation of MOB and HOB creates an alternative route for MP production leveraging safe and sustainably-produced gaseous substrates.

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Muscle Protein Hydrolysates and Amino Acid Composition in Fish

Marine Drugs ◽

10.3390/md19070377 ◽

2021 ◽

Vol 19 (7) ◽

pp. 377

Author(s):

Bomi Ryu ◽

Kyung-Hoon Shin ◽

Se-Kwon Kim

Keyword(s):

Amino Acid ◽

Amino Acid Composition ◽

Acid Composition ◽

Muscle Protein ◽

Fish Muscle ◽

Amino Acid Profile ◽

Industrial Applications ◽

Protein Hydrolysates ◽

Added Value ◽

Degree Of Hydrolysis

Fish muscle, which accounts for 15%–25% of the total protein in fish, is a desirable protein source. Their hydrolysate is in high demand nutritionally as a functional food and thus has high potential added value. The hydrolysate contains physiologically active amino acids and various essential nutrients, the contents of which depend on the source of protein, protease, hydrolysis method, hydrolysis conditions, and degree of hydrolysis. Therefore, it can be utilized for various industrial applications including use in nutraceuticals and pharmaceuticals to help improve the health of humans. This review discusses muscle protein hydrolysates generated from the muscles of various fish species, as well as their amino acid composition, and highlights their functional properties and bioactivity. In addition, the role of the amino acid profile in regulating the biological and physiological activities, nutrition, and bitter taste of hydrolysates is discussed.

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Protein Content and Amino Acid Composition of Certain Fungi Evaluated for Microbial Protein Production

Applied Microbiology ◽

10.1128/am.29.2.250-254.1975 ◽

1975 ◽

Vol 29 (2) ◽

pp. 250-254

Author(s):

C. Christias ◽

C. Couvaraki ◽

S. G. Georgopoulos ◽

B. Macris ◽

V. Vomvoyanni

Keyword(s):

Amino Acid ◽

Amino Acid Composition ◽

Protein Content ◽

Acid Composition ◽

Protein Production ◽

Microbial Protein

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Protein Quality of Rice Drinks Fortified with Bovine and Porcine Blood Plasma

Revista Facultad Nacional de Agronomía Medellín ◽

10.15446/rfnam.v68n1.47835 ◽

2015 ◽

Vol 68 (1) ◽

pp. 7487-7496 ◽

Cited By ~ 1

Author(s):

Piedad Margarita Montero Castillo ◽

Yesid Alejandro Marrugo Ligardo ◽

Lesbia Cristina Julio González

Keyword(s):

Amino Acid ◽

Blood Plasma ◽

Protein Content ◽

Protein Quality ◽

Amino Acid Profile ◽

Food Sources ◽

In Vitro Digestibility ◽

Porcine Blood ◽

Bovine Plasma

The future of nutrition in Colombia, and perhaps in other developing countries, will depend in large part on the ability of food technology to take full advantage of the food sources available in the country and to adapt and develop new products that will vary and complement the diets of the majority of the population at a low cost. The objective of this study was to evaluate the protein quality of rice-based drinks fortified with bovine and porcine blood plasma. Six treatments were prepared with different levels of fortification (14.5%, 18.5% and 29%). The effects of the plasma type and the addition levels on the protein content, the amino acid profile, and the in vitro digestibility of the drinks were observed. The AOAC method was employed for the determination of the protein content; the amino acid profile was created using HPLC. The protein digestibility was determined by subjecting a dispersion of the drink to the action of a multi-enzymatic solution. The protein content increased with the level of fortification. The drinks fortified with bovine plasma (104%) and porcine plasma (89%) presented a better protein quality index than the unfortified drink. The digestibility of the fortified drinks did not demonstrate significant improvements in comparison with the unfortified drink. The chemical score of the drinks fortified with porcine plasma (71.6) and bovine plasma (78.5) showed that the latter had the best nutritional quality.

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Comparison of the fillet yield, protein content and amino acid profile of Clarias gariepinus and the Clarias gariepinus 5 Heterobranchus longifilis hybrid

Aquaculture Research ◽

10.1046/j.1365-2109.2000.00453.x ◽

2000 ◽

Vol 31 (7) ◽

pp. 553-556 ◽

Cited By ~ 4

Author(s):

L K Oellermann ◽

T Hecht

Keyword(s):

Amino Acid ◽

Protein Content ◽

Clarias Gariepinus ◽

Amino Acid Profile ◽

Heterobranchus Longifilis ◽

Fillet Yield

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The Analysis of Protein Level and Amino Acid Profile in Eels (Anguilla marmorata (Q.) Gaimard and Anguilla bicolor) of Lake Poso -

Journal of Pharmacy and Nutrition Sciences ◽

10.29169/1927-5951.2019.09.01.6 ◽

2019 ◽

Vol 9 (1) ◽

pp. 32-37

Author(s):

Jamaluddin ◽

Nur Atina ◽

Yonelian Yuyun

Keyword(s):

Amino Acids ◽

Amino Acid ◽

Protein Content ◽

Protein Level ◽

High Performance ◽

Protein Quality ◽

Essential Amino Acids ◽

Amino Acid Profile ◽

Anguilla Marmorata ◽

Two Samples

In this study used a sample of eel fish species Anguilla marmorata (Q.) Gaimard and Anguilla bicolor from Poso lake that has a high protein content and is a fish endemic to Central Sulawesi. These eels are consumed by the surrounding community of the lake, but the nutritional content remains unknown. The present research was aimed to determine the protein level and amino acid profile of Anguilla marmorata (Q.) Gaimard and Anguilla bicolor eels. The protein level testing used Kjeldahl method, and amino acid profile used High Performance Liquid Chromatography. The results demonstrate the protein level of the two samples Anguilla marmorata (Q.) Gaimard eels have a protein content of 41.84% and Anguilla bicoloreels at 33.75%. Anguilla marmorata (Q.) Gaimard and Anguilla bicolor eels contain 18 types of amino acid, comprised of 9 types of essential amino acids and 9 types of non-essential amino acids. Of the two samples of eel species Anguilla marmorata (Q.) Gaimard and Anguilla bicolor, have complete protein quality because it has all kinds of essential amino acids.

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Production of Serra da Estrela cheese from ultrafiltered sheep’s milk

Emirates Journal of Food and Agriculture ◽

10.9755/ejfa.2020.v32.i5.2109 ◽

2020 ◽

pp. 384

Author(s):

Andréia Maria Faion ◽

Anne Luize Lupatini Menegotto ◽

Ilizandra Aparecida Fernandes ◽

Clarice Steffens ◽

Juliana Steffens ◽

...

Keyword(s):

Amino Acids ◽

Amino Acid ◽

Protein Content ◽

Aspartic Acid ◽

Amino Acid Profile ◽

Protein Yield ◽

Depth Index ◽

Positive Correlations ◽

Serra Da Estrela ◽

Serra Da Estrela Cheese

The objective of this study is to elaborate Serra da Estrela cheese with sheep's milk concentrate by ultrafiltration and characterize it in relation to protein, yield, proteolysis, amino acid profile, and acceptability. The cheese elaborated with concentrate milk (F2) presented an increase of 17% yield, and protein content was 2 times higher than cheese without concentrate milk (F1). On the 30thday of storage F2 presented an increase of the amino acids and also of proteolysis extension and depth index in relation to the 1st day. Also presented better sensorial characteristic in relation to F1. Were observed positive correlations (>0.85) between acceptability in relation to protein, depth index, extensionand extension index, valine, methionine, serine, phenylalanine aspartic acid, valine andproline. Cheese elaborated with concentrate milk and coagulated with thistle flower is one alternative to increase cheese yield with differential sensorial characteristics.

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