scholarly journals DOMESTICATION AND FORMULATION OF RHIZOPODOPSIS JAVENSIS AS A TEMPEH STARTER

2021 ◽  
Vol 15 (3) ◽  
pp. 1
Author(s):  
GAYUH RAHAYU ◽  
EFRIWATI EFRIWATI ◽  
SEPTINA VERONICA
Keyword(s):  
Growth Rate ◽  
Water Content ◽  
Growth Temperature ◽  
Wild Strain ◽  
Optimal Growth ◽  
Rice Flour ◽  
Fermented Foods ◽  
Rhizopus Microsporus ◽  
Spore Viability ◽  
Optimum Growth Temperature

ABSTRACT Domestication of wild fungal strains involved in the manufacture of traditional fermented foods often occurs spontaneously. Rhizopodopsis javensis (Rh. javensis) is taxonomically close to Rhizopus. The wild strain Rhizopodopsis javensis has found in cool climates can be developed as a starter in tempeh production in temperate regions. Before formulating it as a tempeh starter, a wild strain of Rh. javensis needs to be domesticated in human-made niches. A wild strain of Rh. javensis was domesticated by subculture using rice flour media at optimum growth temperature and carried out every five days. The spore's density and viability and the starter's water content were used to determine its quality. The results showed that Rh. javensis grew optimally at 22 ℃. With seven-time subcultures using rice flour media, the domestication process did not change the Rh. javensis growth rate and colony appearance. The growth rate of Rh. javensis is relatively the same as that of commercial tempeh starter and pure R. microsporus var. oligosporus, at each optimal growth temperature. In the rice flour media as a carrier, Rh. javensis produces spore's density that is relatively the same as that of commercial tempeh starter but with lower spore's viability and higher water content. Therefore, Rh. javensis cannot be used as a starter to produce tempeh in the temperate region. The carrier material and drying processes still need to be modified to increase spore viability and improve the overall quality, including the starter's lifespan. Keywords: food fermentation, Rhizopus microsporus var. oligosporus, spore's viability, starter quality, wild strain ABSTRAK Domestikasi galur liar kapang yang terlibat dalam dalam pembuatan makanan fermentasi tradisional, sering terjadi secara spontan. Rhizopodopsis javensis (Rh. javensis) merupakan salah satu galur liar kapang yang memiliki hubungan taksonomi dekat dengan Rhizopus. Strain liar ini ditemukan di daerah beriklim sejuk, sehingga berpotensi untuk dikembangkan sebagai starter tempe untuk produksi di daerah beriklim sedang. Untuk mendapatkan kultur yang tumbuh subur di relung (niches) buatan manusia, strain liar Rh. javensis perlu didomestikasi terlebih dahulu. Penelitian ini bertujuan untuk mendomestikasi strain Rh. javensis liar yang dilanjutkan dengan memformulasikannya sebagai starter tempe. Domestikasi dilakukan dengan menumbuhkan strain liar Rh. javensis pada media tepung beras pada suhu pertumbuhan optimum dan diulangi setiap lima hari. Kerapatan dan viabilitas spora, serta kadar air starter digunakan sebagai penilaian keberhasilan starter. Hasil penelitian menemukan Rh. javensis tumbuh optimal pada suhu 22 ℃. Domestikasi dengan cara subkultur koloni Rh. javensis pada media tepung beras selama 7 kali tidak mengubah kecepatan pertumbuhan Rh. javensis dan penampakan koloni. Laju pertumbuhan Rh. javensis relatif sama dengan laju pertumbuhan starter tempe komersial dan R. microsporus var. oligosporus murni, pada suhu optimum pertumbuhan masing-masing. Formulasi tepung beras sebagai media pembawa starter Rh. javensis, menghasilkan kerapatan spora yang relatif sama dengan starter tempe komersial, namun viabilitas sporanya rendah dan kadar airnya tinggi. Starter Rh. javensis belum dapat digunakan untuk membuat tempe. Substrat dan proses pengeringan masih perlu dimodifikasi untuk meningkatkan viabilitas spora dan kualitas starter tempe secara keseluruhan, termasuk umur simpan starter. Keywords: fermentasi makanan, kualitas starter, Rhizopus microsporus var. oligosporus, strain liar, viabilitas spora

Phaeotheca dimorphospora sp.nov.: description et caractéristiques culturales

1994 ◽  
Vol 72 (6) ◽  
pp. 808-817 ◽  
Author(s):  
Pierre DesRochers ◽  
G. B. Ouellette
Keyword(s):  
Growth Rate ◽  
Growth Temperature ◽  
Type Species ◽  
Optimal Growth ◽  
Outer Wall ◽  
Dutch Elm Disease ◽  
Optimal Growth Temperature ◽  
Ophiostoma Ulmi ◽  
Mother Cells

An unknown fungus isolated from an elm branch and inhibitory against Ophiostoma ulmi in vitro is described as Phaeotheca dimorphospora sp.nov. This dematiaceous deuteromycete propagates by endoconidia released after exfoliation of chlamydospore outer wall, as in mother cells of the type species Phaeotheca fissurella. However, P. dimorphospora differs from the type species by producing hyaline secondary ameroconidia between the endoconidial masses. Other ameroconidia, similar to the secondary ameroconidia, are produced through the chlamydospore outer wall. The optimal growth temperature of P. dimorphospora is 23 °C, whereas it is 15.5 °C for the type species. On media containing a high dextrose concentration (30 g ∙ L−1), colonies of P. dimorphospora are gray and crustose and grow slowly, at least initially. Conversely, on media with a low dextrose concentration (5 or 10 g ∙ L−1) colonies have a faster growth rate and appear whitish or ivory and fluffy. Key words: Phaeotheca dimorphospora, diagnosis, inhibition, Ophiostoma ulmi, Dutch elm disease.

Optimal growth temperature hypothesis: Why do anchovy flourish and sardine collapse or vice versa under the same ocean regime?

2007 ◽  
Vol 64 (5) ◽  
pp. 768-776 ◽  
Author(s):  
Akinori Takasuka ◽  
Yoshioki Oozeki ◽  
Ichiro Aoki
Keyword(s):  
Growth Rate ◽  
Growth Temperature ◽  
Growth Rates ◽  
Synergistic Effects ◽  
Larval Growth ◽  
Optimal Growth ◽  
Regime Shifts ◽  
Optimal Growth Temperature ◽  
Sea Temperature ◽  
Japanese Sardine

The out-of-phase population oscillations between anchovy and sardine have been attributed to climate changes. However, the biological processes causing these species alternations have remained unresolved. Here we propose a simple "optimal growth temperature" hypothesis, in which anchovy and sardine regime shifts are caused by differential optimal temperatures for growth rates during the early life stages. Dome-shaped relationships between growth rate and sea temperature were detected for both Japanese anchovy (Engraulis japonicus) and Japanese sardine (Sardinops melanostictus) larvae based on otolith microstructure analysis. The optimal growth rate for anchovy larvae occurred at 22.0 °C, whereas that for sardine larvae occurred at 16.2 °C. Ambient temperatures have historically fluctuated between these optima, which could lead to contrasting fluctuations in larval growth rates between the two species. This simple mechanism could potentially cause the shifts between the warm anchovy regime and the cool sardine regime in the western North Pacific. Although retrospective analysis suggested synergistic effects of other factors (e.g., trophic interactions and fishing), the optimal growth temperature concept would provide a possible biological mechanism of anchovy and sardine regime shifts.

EFFECTS OF LOW TEMPERATURES ON THE GROWTH OF MARINE BACTERIA

1933 ◽  
Vol 8 (1) ◽  
pp. 489-505 ◽  
Author(s):  
ERNEST HESS
Keyword(s):  
Growth Rate ◽  
Pseudomonas Fluorescens ◽  
Crop Yield ◽  
Marine Bacteria ◽  
Growth Temperature ◽  
Low Temperatures ◽  
Optimum Growth ◽  
Optimum Growth Temperature ◽  
Plate Counts ◽  
Logarithmic Growth

Growth of Pseudomonas fluorescens, Flavobacterium deciduosum, and B. vulgatus (all of marine origin) in buffered nutrient broth at 37°, 20°, 5°, 0° and −3 °C. has been followed quantitatively by means of plate counts. Maximum crops were obtained at 5 °C. in all cases, and higher total crops at 0° and −3° than at 37° and 20°. Maximum crop yield is considered a better criterion for optimum growth temperature than the growth rate during logarithmic growth. These marine bacteria are therefore considered to be truly psychrophilic.

scholarly journals Characteristics of Phomopsis juglandina (Sacc.) Hohn. Associated with Dieback of Walnut in the Climatic Conditions of Southern Romania

Agronomy ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 46
Author(s):  
Cristina Mihaescu ◽  
Daniel Dunea ◽  
Adrian Gheorghe Bășa ◽  
Loredana Neagu Frasin
Keyword(s):  
Growth Temperature ◽  
Potential Evapotranspiration ◽  
Optimal Growth ◽  
Climatic Conditions ◽  
Cultural Characteristics ◽  
Optimal Growth Temperature ◽  
Conidial State ◽  
Optimal Ph

Phomopsis juglandina (Sacc.) Höhn., which is the conidial state of Diaporthe juglandina (Fuckel) Nitschke, and the main pathogen causing the dieback of branches and twigs of walnut was recently detected in many orchards from Romania. The symptomatological, morphological, ultrastructural, and cultural characteristics, as well as the pathogenicity of an isolate of this lignicolous fungus, were described and illustrated. The optimum periods for infection, under the conditions prevailing in Southern Romania, mainly occur in the spring (April) and autumn months (late September-beginning of October). Strong inverse correlations (p < 0.001) were found between potential evapotranspiration and lesion lengths on walnut branches in 2019. The pathogen forms two types of phialospores: alpha and beta; the role of beta phialospores is not well known in pathogenesis. In Vitro, the optimal growth temperature of mycelial hyphae was in the range of 22–26 °C, and the optimal pH is 4.4–7. This pathogen should be monitored continuously due to its potential for damaging infestations of intensive plantations.

scholarly journals Optimising the DPPH Assay for Cell-Free Marine Microorganism Supernatants

Marine Drugs ◽  
2021 ◽  
Vol 19 (5) ◽  
pp. 256
Author(s):  
Yehui Gang ◽  
Tae-Yang Eom ◽  
Svini Dileepa Marasinghe ◽  
Youngdeuk Lee ◽  
Eunyoung Jo ◽  
...  
Keyword(s):  
Water Content ◽  
Antioxidant Activities ◽  
Fermented Foods ◽  
Solution Stability ◽  
Marine Microorganism ◽  
Marine Microorganisms ◽  
Dpph Assay ◽  
Aqueous Methanol ◽  
Potential Applications ◽  
Pseudoalteromonas Rubra

Antioxidants prevent ageing and are usually quantified and screened using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. However, this assay cannot be used for salt-containing samples, such as the cell-free supernatants of marine microorganisms that are aggregated under these conditions. Herein, the DPPH solvent (methanol or ethanol) and its water content were optimized to enable the analysis of salt-containing samples, aggregation was observed for alcohol contents of >70%. The water content of methanol influenced the activities of standard antioxidants but did not significantly affect that of the samples. Based on solution stability considerations, 70% aqueous methanol was chosen as the optimal DPPH solvent. The developed method was successfully applied to the cell-free supernatants of marine bacteria (Pseudoalteromonas rubra and Pseudoalteromonas xiamenensis), revealing their high antioxidant activities. Furthermore, it was concluded that this method would be useful for the screening of marine microorganism–derived antioxidants, which also has numerous potential applications, such as salt-fermented foods.

scholarly journals 261 Increasing dietary amylose reduces rate of starch digestion and increases microbial fermentation in weaned pigs

2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 86-86
Author(s):  
F P Y Tan ◽  
L F Wang ◽  
E Beltranena ◽  
R T Zijlstra
Keyword(s):  
Growth Rate ◽  
Block Design ◽  
Optimal Growth ◽  
Metabolite Profile ◽  
Proximal Colon ◽  
Starch Digestion ◽  
Gut Health ◽  
Weaned Pigs ◽  
Ileal Digestibility ◽  
Beneficial Effects

Abstract Beneficial effects of SCFA in modulating gut health stimulated interest on dietary strategies to increase intestinal microbial activity and digesta SCFA. Amylose has lower apparent ileal digestibility (AID) than amylopectin. In the large intestine, undigested starch is fermented by microbes producing SCFA. The objective was to determine effects of increasing dietary amylose on starch flow and metabolite profile along the intestinal tract in weaned pigs. Weaned pigs (n=32; initial BW, 8.4 kg) were randomly allocated to 4 diets containing 67% starch with 0, 20, 35, or 70% amylose in a randomized complete block design. On day 21, pigs were euthanized to collect digesta and feces for evaluating starch digestion and metabolite profiles. Apparent hindgut fermentation (AHF) was calculated as apparent total tract digestibility minus AID. Feed intake was 12% lower (P &lt; 0.05) and growth rate was 18% lower (P &lt; 0.05) for pigs fed 70% amylose than pigs fed 0, 20, or 35% amylose. Feed efficiency was greatest (P &lt; 0.05) for pigs fed with 35% amylose. The AID of starch was 44% lower (P &lt; 0.05) in pigs fed 70% amylose. Starch was completely digested by the proximal colon in pigs fed 0, 20, or 35% amylose, but AHF of starch was 14% greater (P &lt; 0.05) in pigs fed 70% amylose. Increasing dietary amylose did not alter digesta SCFA in the small intestine, but increased (P &lt; 0.05) digesta SCFA in the cecum, specifically acetate and total SCFA, and increased (P &lt; 0.05) propionate and valerate in all sections of the colon. In conclusion, increasing dietary amylose in weaned pigs stimulated hindgut fermentation of starch with a corresponding increase in digesta total SCFA in the cecum and colon. Optimizing dietary amylose may exert its effect as dietary prebiotic while promoting an optimal growth rate in young pigs.

The correlation between genomic G + C and optimal growth temperature of prokaryotes is robust: A reply to Marashi and Ghalanbor

2005 ◽  
Vol 330 (2) ◽  
pp. 357-360 ◽  
Author(s):  
Hector Musto ◽  
Hugo Naya ◽  
Alejandro Zavala ◽  
Hector Romero ◽  
Fernando Alvarez-Valin ◽  
...  
Keyword(s):  
Growth Temperature ◽  
Optimal Growth ◽  
Optimal Growth Temperature

Properties comparison of GaN epilayers deposited under different growth temperatures

2011 ◽  
Vol 19 (1) ◽  
Author(s):  
P. Wang ◽  
H. Yan ◽  
B. Cao ◽  
W. Wei ◽  
Z. Gan ◽  
...  
Keyword(s):  
Growth Temperature ◽  
Structural Characteristics ◽  
Chemical Vapour ◽  
Optimal Growth ◽  
Good Method ◽  
Test Results ◽  
Temperature Deposition ◽  
Metalorganic Chemical Vapour Deposition ◽  
Gan Film

AbstractUndoped GaN epilayers were grown on c-plane sapphire substrates under different growth temperatures by metalorganic chemical vapour deposition (MOCVD). The optical and structural characteristics of these grown samples were studied and compared. It was found that the crystalline quality of GaN film deposited at 1050°C was better that of other samples. Photoluminescence spectra showed that the intensities of yellow luminescence band of the samples decreased as the growth temperature increased. All above test results demonstrate that high temperature deposition can serve as a good method for high-quality GaN epilayer growth and there exists an optimal growth temperature.

scholarly journals UTILITY MAXIMIZATION IN A BINOMIAL MODEL WITH TRANSACTION COSTS: A DUALITY APPROACH BASED ON THE SHADOW PRICE PROCESS

2014 ◽  
Vol 17 (04) ◽  
pp. 1450022 ◽  
Author(s):  
CHRISTIAN BAYER ◽  
BEZIRGEN VELIYEV
Keyword(s):  
Growth Rate ◽  
Asymptotic Expansion ◽  
Transaction Costs ◽  
Continuous Time ◽  
Shadow Price ◽  
Optimal Growth ◽  
Order Effect ◽  
Explicit Construction ◽  
Binomial Model ◽  
Price Process

We consider the problem of optimizing the expected logarithmic utility of the value of a portfolio in a binomial model with proportional transaction costs with a long time horizon. By duality methods, we can find expressions for the boundaries of the no-trade-region and the asymptotic optimal growth rate, which can be made explicit for small transaction costs (in the sense of an asymptotic expansion). Here we find that, contrary to the classical results in continuous time, see Janeček and Shreve (2004), Finance and Stochastics8, 181–206, the size of the no-trade-region as well as the asymptotic growth rate depend analytically on the level λ of transaction costs, implying a linear first-order effect of perturbations of (small) transaction costs, in contrast to effects of orders λ1/3 and λ2/3, respectively, as in continuous time models. Following the recent study by Gerhold et al. (2013), Finance and Stochastics17, 325–354, we obtain the asymptotic expansion by an almost explicit construction of the shadow price process.

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