References: Molds and yeasts . . .

Mushrooms are for sexual reproduction (~flowers)Mycelium = body of the fungus

Hyphae = the “bricks” from which the mushroom is built

What are fungi?

• Fungi belong to their own special ‘kingdom’ as they differ from both plants and animals. Fungi are eukaryotic cells.

• The fungal kingdom is largely hidden from our view underground and we usually only see the "fruit" of a fungus. Fungi can exist as single cells or chains of cells together. The living body of a fungus is called a mycelium and is made up of a branching network of filaments known as hyphae.

• Fungal mycelia are usually hidden in a food source like wood and we only know they are there when they develop mushrooms or other fruiting bodies. Some fungi only produce microscopic fruiting bodies and we never notice them.

Fungal hyphae growing - contain chains of cells .

Fungi are made of hyphae (cells joined in thread-like strands)

Interesting fungi:

• One of the largest living organisms in the world is a specimen of the fungus Armillaria ostoyae which covers 1,500 acres in Washington State, USA and seems to be 400-1,000 years old.

• The only evidence of the fungus are clumps of golden mushrooms that pop up in autumn when it rains. Largely this fungus is seen underground and forms huge rhizomorphs (root like structure).

Single or multi-celled eukaryote heterotrophic, absorptive nutrition, chitinous cell walls, Have chitin as the

major structural component of cells which stores energy as glycogen Live in food source or go dormant in low

humidity

Discussion Question

Which of the following is most closely related to a mushroom (fungus)?

Why do you think so?

From phylogeny Fungi most closely related to

animals (why it’s harder to get rid of fungal infections than bacterial):

similar biochemistry - store carbon/energy as glycogen in cells (not starch like plants)

2. Symbiotic fungi:

Mycorrhizae: plant roots and fungi

“myco” = fungus and “rhiza” = root

Advantages to fungi

Plants are a dependable and abundant source of

carbohydrates

Advantages to plant

I. Fungi are better than plants at acquiring mineral nutrition (P,K, N) from the soil.

II. Fungi improve a plant’s access to water

III. can break molecules down into useable

forms

IV. can access greater soil volume

Fungi can access more of the soil

1. Hyphae are smaller than plant roots

Hyphae are 1/500th the diameter of a plant root hair

Root Hair

hyphae

fungi expand the surface area available for nutrient uptake

Predatory fungi, catch and digest other organisms (like nematodes)

But still absorptive nutrition! Just have to catch it first…

M YXOM YCOTA

M ASTIGOM YCOTINA ZYGOM YCOTINA ASCOM YCOTINA DEUTEROM ICOTINA(FUNGI IM PERFECTI)

BASIDIOM YCOTINA

EUM YCOTA

FUNGI

Asexual (ANAMORPH) Sexual (TELEOMORPH) SPORE TYPES

Zoospores Sporangiospores Conidiospores Ooospores Zygospores Basidiospores

Why should you care about fungi?A few reasons:I. They make foods we like to eat

II. Mycorrhizae are responsible for plant life on land and high productivity rates

III. They decompose wood and organic matterIV. Penicillin and other medicines

V. Infection and disease

VI. Food borne disease

به قادر قارچها از كمي تعداددليل به بيماريند : ايجاد

- انسان بدن حرارت درجه - احيا – اكسيداسيون كاهش

- بدن دفاعي سيستم

Cutaneous mycoses

Dimorphic systemic mycoses

Opportunistic mycoses

Subcutaneous mycoses

Superficial mycoses

Use of microbes to manufacture consumable materials

Use of microbes to generate organic compounds

39

Examples of industrial products

Examples of industrial enzymes

Industrial processes harvest primary metabolites from the log phase, and secondary metabolites from the stationary phase.

43

The origins of primary and secondary microbialMetabolites harvested by industrial processes.

A cell culture vessel used to mass-producePharamaceuticals.

A schematic diagram of an industrial fermentor

46

The general layout of a fermentation plant

Penicillium1928,Dr. Andrew Fleming, Working in London, noticed that mold growing on staph bacterial culture plates, had killed the pathogen

zone of dead bacteria

Penicillin kills bacteria by interfering with their ability to synthesize cell wall.

• Escherichia coli were incubated in penicillin for 30 minutes. • The bacteria lengthen, but cannot divide. Eventually the weak cell wall ruptures (last panel

Why do fungi make antibiotics?Fungi produce antibiotics for the same reason we need them:

to fight off bacterial infections

Biotechnology & industrial microbiology

• Biotechnology – the use of microbiological and biochemical techniques to produce useful products – proteins or DNA sequences

• Recombinant DNA techniques – methods to study andmanipulate DNA to genetically alter organisms with useful traits to clone genes

• Genetic engineering – deliberately alter an organism’s genetic information

Genetic engineeringTools:

vectors :

plasmids,

bacteriophage

•restriction enzymes

Restriction enzymes

Biotechnology & industrial microbiology

protein productionpharmaceutical proteins

Biotechnology & industrial microbiology

vaccineshepatitis B

plantspest-resistant plants corn, cotton, tomatoes Bt toxin from B. thuringensisherbicide resistant plants soybeans, cotton, cornimproved nutritional value β-carotene in rice higher iron in rice

MycotoxinsA Biological Perspective

Mycotoxin Chain of Events

http://www.foodtech-international.com/papers/images/mycotoxins/figure1.gif

What is a Mycotoxin?

• Secondary metabolites (chemicals) of a fungus that produce toxic results in another organism.

• Cytotoxic: disrupt cell structures such as membranes, and processes such as protein, DNA, and RNA synthesis.

• Lack of visible appearance of fungus does not negate presence of mycotoxins. Toxins can remain in the organism after fungus has been removed.

• Can be heat stable, not destroyed by canning or other processes.

http://www.mycotoxins.info/myco_info/field/formationFungGrwth/fungi.jpg

Mycotoxins• fungal metabolites • are toxic when consumed by animals or

humans. • They can accumulate in corn, cereals,

and other food • during transportation and during

improper storage favorable for the growth of the toxin-producing fungus or fungi.

Three mycotoxins• account for 99 percent of the diagnosed

animal mycotoxicoses1. aflatoxin,2. zearalenone and 3. deoxynivalenol. • Deoxynivalenol (also called DON,

vomitoxin) and zearalenone (estrogenic mycotoxin) often coexist in corn with Fusarium graminearum.

: زرد برنج P. islandicum, P. rugulosum, P. citreoviride,

P. citrinum:... ،هپاتوما.1 : حاوی سیکلوپپتید اگزوتوکسین، ایسلندیتوکسین

هپاتوتوکسین کلرین،.2 : فاز هپاتوتوکسین، آندوتوکسین، لوتوسکرین

هپاتوما: مزمن

راگولوزین توسطP. rugulosum, P. brunneum, P.

Tardum. شود می ایجاد برنج در کمتر سمیت

:سیترینینP. citrinum, A. candidus, A, terreus

- ) شود ) می موش در نفروز موجب :) هائی ) گونه فرکونتیک اسید سیترئومایستین

آسیب مایسس، سیترئو و سیلیوم پنی ازکلیوی

قلبی بری بری :،قلبی بری بری سیترئوویریدین P. citreoviride، : استفراغ، بعد و شروع عصبی سیستم گرفتاری با

روز سه طی مرگ تنفس، توقف و تشنجاختصاصی • عالئم و فصلی سریع، بیماریتنفسی، • آسیبهای و فلجمرکزی • اعصاب سیستم در

ارگوتیسم و غالت C. purpurea, C. microcephala, C. nigricans,

C. paspali چاوداربخصوص طریق از. هم علوفه انواع قحطی های دوره در

: هوائی و آب شرایط بهار ،خشک تابستان مرطوب و پرباران های دوره

: آسکوسپور،* کالهدار قارچ اسکلروتیا، زدن جوانهزدنن جوانه مادگی، روی اسپورها

مسمومیت مشخصات : عضالنی، دردهای سستی، ارگوتیسم گانگرنوس

گانگرن و نکروز سوزنی، سوزن احساس :،خارش گرفتار، مرکزی اعصاب سیستم تشنجی

. مرگ و تشنج عضالنی، درد حسی، بی - : د* از شده مشتق آمید های اسید فعال ترکیب

اسید لیزرزیک : صاف* عضالت توسیک اکسی اثر

Alimentary Toxic Aleukia (ATA)• During World War II, in Soviet Union, corn grain

left to over-winter becomes contaminated with T-2 toxin.

• Severe mycotoxicosis occurs.• Symptoms include burning in the mouth,

esophagus, tongue, and stomach.• Blood marrow formation is halted and anemia

develops.• Hemorrhage of nose, gums, mouth and stomach occurs.

http://www.firstchoicemold.com/images/molds/Fusarium-sp..jpg

فوزاریوم و و غالتA.T.A(alimentary toxic aleukia)

و : اغلب prosomilletگندم لیپوتوکسول و اسپوروفوزارین و پوآفوزارین استفراغ موجب

fumonisins carcinogens produced in fungus-infected corn

Red Mold Disease or Black Spot روزئوم فوزاریوم و نیویل فوزاریوم اغلب جو و گندم اسهال و استفراغ و درد سر

Endemic Balkan Nephropathy ادم و خونی کم کلیوی، اکراتوکسین مصرف... ذرت دوسر، جو گندم، جو،

علوفه Facial Eczema: Pitomyces chartarum

علوفهاسپوریدسمین کنندگان نشخوار در به حساسیت زردی، وزن، کاهش کبدی، آسیب

( ثانویه( عالمت صورت اگزمای نور

Stachybotryotoxicoses Stachybotrys atra

Atypical form :،سریع زیاد، ساعت، 72مصرفمرگ و تنفسی دستگاه فلج عصبی، عالئم

Typical form :،لکوسیتها کاهش کم، مصرفمخاطی نکروتیک های زخم

If aflatoxin: is consumed regularly by sensitive young animals at

50 to 100 parts per billion (ppb), the result can be fatal liver cancer;

in older or mature animals, the effect may only be minor.

Most species of animals appear to be susceptible,although susceptibility may vary. Animals on a protein-deficient diet are more sensitive

to aflatoxin injury than are those on a well-balanced ration.

aflatoxins carcinogens produced in fungus-infected

grains and nut products

I) Giới thiệu

• Có 4 loại nấm sản xuất ra độc tố aflatoxin. Đó là: Aspergilus-flavus, A. Parasiticus, A. nomius và A. pseudotamarii.

A. flavus A. Parasiticus

I) Giới thiệu

• Khí hậu nhiệt đới và cận nhiệt, nhiệt độ môi trường trên 270C, điều kiện lưu trữ ẩm ướt.

• Trong các sản phẩm nông nghiệp: bắp, đậu phộng và hạt bông

• Trong điều kiện bảo quản không tốt

• Đôi khi sữa, trứng, thịt cũng bị phát hiện có aflatoxin

Bắp bị nhiễm nấm mốc

I) Giới thiệu

2) Công thức cấu tạo của aflatoxin Aflatoxin là một mycotoxin gồm có 17 loại,

trong đó có 4 loại chính là aflatoxin B1, B2, G1, G2 (AFB1, AFB2, AFG1, AFG2).

AFB1: C17H12O6

AFB2: C17H14O6

AFG1: C17H12O7

AFG2: C17H14O7

I) Giới thiệu• Aflatoxin đươc hấp thu vào gan nhiều nhất

(chiêm khoảng 17% lương aflatoxin cua cơ thê) tiêp theo là ơ thận, cơ, mô mơ, tuy, lách...

• 1 kg thức ăn chỉ cần nhiễm 2 miligam cũng đã đu làm hỏng gan

Gan bình thường và bị nhiễm độc

II. Phòng ngừa và điều trị

C. Điều trị ngộ độc aflatoxin

Với gia súc, gia cầm:

Gia cầm chếtdo ngộ độc

II. Phòng ngừa và điều trị

Với người:

Người bị ngộ độc Máy rửa dạ dày

Aflatoxin B1

Aflatoxin B1: Background

• Hepatotoxic mycotoxin (toxin from a fungus) produced by the fungi Aspergillus flavus and Aspergillus parasiticus

• Causes aflatoxicosis and liver disease

• Aspergillus spp. grow ubiquitously on plants and crops from tropical and subtropical areas: peanuts, figs, spices, corn, maize, Brazil nuts, pecans, walnuts, soybeans, pistachios, wheat and grains

Background

• The carcinogenic metabolite of Aflatoxin B1 is found in the milk of mammals who consume contaminated crops

• Aspergillus growth and Aflatoxin B1 production is dependant upon the temperature, humidity, host plant type, and the strain of fungus; high humidity usually required for growth

• Outbreaks more common in developing countries due to improper drying and storage of crops and a lack of food inspections

Background• Outbreaks occur in groups because of a

shared contaminated food supply and the optimal weather conditions for Aspergillus growth

• First recorded outbreak was in England in 1960, where 100000 turkeys died.

Background

• In 1974 in clustered villages in India, 397 recorded cases with 108 deaths; this was preceded by an outbreak in the local dogs

• In Kenya in 2004, maize contaminated with Aflatoxin B1 caused liver disease and jaundice in 317 people; 125 people died

The use of antifungal agents is often too costly for farmers in developing countries

Toxicity Parameters• Exposure to 2-6 mg of aflatoxin by consumption daily for one month is cited to have toxic effects (David et al. 1994)

• Consumption of 55 µg/ kg of aflatoxin daily for an unknown period of time will be fatal (FDA 1992)

• However, levels found to be toxic are inconsistent between various studies.

•Reasons for this include:

1) most studies were done in African countries where prevalence of Heptatitis B is very high

2) Active HepB virus is known to be synergistic with aflatoxin in causing toxicities and hepatocellular carcinoma

Toxicity cont’d

3) most studies were done on rats, and it can be difficult to extrapolate these results to humans

4) There is a double standard for accepted aflatoxin levels due to economic stress: • food intended for human consumption must have less

than 30ppb, and animal feed may be as high as 30ppb in America

Mechanism of Action

• AFB1 is oxidized by CYT P450 in the liver into AFB1-8,9-epoxide which is the major metabolite that exerts hepatotoxic effects

• The 8,9 epoxide is neutralized by conjugation in the liver with GSH (glutathione) by glutathione-S-transferase, an enzyme abundant in some animals (mice), but which rats and humans are relatively deficient in.

Mechanism of Action

• The 8,9 epoxide binds preferentially to mitochondrial DNA hindering ATP production and FAD/NAD-linked enzymatic functions. The result is reduced mitochondrial function and increased prevalence of mitochondrial directed apoptosis

• GSH has many roles in membrane maintenance and stability as well as reducing oxidative stress. Its reduction further enhances the damage to critical cellular components (DNA, lipids, proteins) by the 8,9 epoxides

Mechanism of Action

• Abnormally high levels of ROS are found in cells affected by aflatoxin due to uncoupling of metabolic processes resulting from the lack of GSH for GSH-peroxidase catalysis of O2· to H2O2 leading to lipid peroxidation and compromised cell membranes

• One of the most serious effects of the AFB1-8,9-epoxide metabolite is it reacts with amino acids in DNA and forms an adduct.

• This adduct is fairly resistant to DNA repair processes and thus this gene mutation may cause carcinoma of the liver.

• CYP 3A4 is the major CYP 450 enzyme responsible for activation of AFB1 into the epoxide form.

• However, the liver can detoxify AFB1 by oxidizing it to other metabolites such as AFQ1 which has very little cancer-causing potential. These are usually excreted in urine with little effect on the body.

AFB1-8,9-epoxide Is Cancer-causing!!

(Novoa and Diaz 2006)

When the epoxide combines with DNA or RNA, it forms what is known as an adduct

How Does Aflatoxin Cause Cancer?

•Inactivation of the p53 tumor suppressor gene enables mutation of Codon 249 (primary gene mutation caused specifically by AFB1)

•This shuts off the gene and potentially allows for uncontrolled cell proliferation.

• But exposure to aflatoxin does not necessarily predispose you to liver cancer.

•The human body is capable of genetic repairs and some people are more resistant to cancer than others

Other Adverse Effects of AFB1-8,9-epoxide

- Lipid accumulation in the liver due to decreased lipid transport and reduced oxidation

-Symptoms of liver failure occur with acute aflatoxicosis:

-Jaundice

-ascites (fluid build up)

-portal hypertension

-necrosis of the liver

Other Adverse Effects of AFB1-8,9-epoxide

• The binding of the epoxide with proteins may:– Inhibit the protein from

performing its enzymatic functions

– Create a reservoir of the toxin in proteins, prolonging exposure

Metabolism

• Both metabolized and unmetabolized aflatoxin is excreted mostly in urine. It is also excreted in milk, stool, feces, and saliva (which may be swallowed and re-enter the GI tract)

Other Chronic Effects of Aflatoxin

• Immunological Suppression– Using animal models, AFB1 has been shown

to impair normal immune function either by reducing phagocytic activity or reduce T cell number and function.

• Nutritional Interference– Aflatoxin is shown to have a dose response

relationship between exposure to aflatoxin and rate of growth among small children. In addition, it also interferes in nutrient modification such as Vitamin A or D in animal models.

• In general, the incidence of toxicity and cancer is quite low after toxin exposure

• The liver is very efficient in removing it from the body in most cases

• However, children are more susceptible to toxicity because their metabolic enzyme systems are not fully developed

The Good News…

Treatment

• Inactivation of toxin before ingestion:– Synergistic combination of gamma radiation

and hydrogen peroxide degrades the toxin– Treatment of corn with ammonia– Dichlorvos inhibits aflatoxin B1 biosynthesis– NaHSO3 soak for corn also shows beneficial

results

Treatment• After ingestion

– Treatment with antibiotics or other drugs has little effect– UV doses increased rate and extent of removal of aflatoxin B12

adducts from DNA– Chlorophyll intervention: supplement diets with foods rich in

chlorophyll• Blocks carcinogen bioavailability

– Certain types of flavanoids found in grapefruit stimulates the microsomal activation of aflatoxin B1 to the exo-8,9-epoxide which is not harmful

– Administration of drugs that induce hepatic detoxification enzymes (ethoxyquin, butylated hydroxyanisol, butylated hydroxytuluene, phenobarbital)

– Oltipraz inhibits aflatoxin B1 mediated hepatocarcinogens in rats

– Induction of an antibody that would allow the body to identify and remove the toxin upon exposure (aflatoxin B1- lysine adduct monoclonal antibody)

THE END

Literature Cited• Urrego Novoa JR and Diaz GJ. 2006. Aflatoxins and its mechanisms of toxicity in hepatic cancer.

Rev.fac.med.unal. 54: 108-116. Available from World Wide Web: <http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0120-00112006000200006&lng=en&nrm=iso>.

• Eaton DL and Gallagher EP. 1994. Mechanism of aflatoxin carcinogenesis. Annual review of pharmacology and toxicology 34: 135-172.

• U.S. Food And Drug Administration. “Bad Bug Book: Alfatoxins”. June 14, 2006. <http://www.cfsan.fda.gov/~mow/chap41.html>

• Center For Disease Control. Morbidity and Mortality Weekly Report. “Outbreak of Aflatoxin Poisoning - Eastern and Central Provinces, Kenya, January-July 2004”. Sept. 3, 2004. <http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5334a4.htm>

• Reddy, S.V., Waliyar, Farid. “Properties of aflatoxin and it producing fungi”. Oct. 11, 2007. http://www.icrisat.org/aflatoxin/aflatoxin.asp

• R. J. Verma. 2004. Aflatoxin Cause DNA Damage. International Journal of Human Genetics 4(4): 231-236.

• J. H. Williams, et al. 2004. Human aflatoxicosis in developing countries: a review of toxicology, exposure, potential health consequences, and interventions. The American Journal of Clinical Nutrition. 80:1106 –22

Literature Cited• Google Images: http://www.takingdownwords.com/photos/uncategorized/turkey.jpg• Google Images: http://www.sfws.auburn.edu/sfnmc/class/fy614/fungicide.jpg• Google Images: http://www.cals.cornell.edu/cals/public/impact/images/cows-eating-dairy-impact.jpg• Google Images: http://www.revmed.unal.edu.co/revistafm/v54n2/imagenes/v54n2a06fig5.jpg• Google Images: http://www.merck.com/media/mmhe2/thumbnails/tn_10116ap.jpg• M. Smela et. al; The chemistry and biology of aflatoxin B1: from muational spectrometry to carcinogenesis.

Carcinogenesis, vol.22, p 535-45, 1994• M. McLean, M. Dutton; Cellular interactions and metabolism of aflatoxin: an update. Pharmacological

Therapeutics, vol.65, p163-92, 1995• Google Images: http://www.biocom.arizona.edu/graphics/images/projects/liver.jpg• Google Images: http://129.215.156.68/Images/Asexual%20structures%20of%20Aspergillus%20niger.jpg

Microbiology of Fermented Foods

major fermentations used are lactic, propionic, and ethanolic fermentations

Fermentation

Any partial breakdown of carbohydrates taking place in the absence of oxygen.

Fermented Foods

Alcoholic Beverages Alcohol is produced from fermentation

by the yeast Saccharomyces cerevisiae Bread Dairy Products Other Fermented Foods

Fermented Foods Beer

Produced by the fermentation of malted grain Malted grain: Grain that has been

allowed to germinate, then dried Germinating the grain causes the

production of a number of enzymes, most notably α- and β-amylase

Malted grains that may be used are barley, rye, or wheat

Unmalted grains, such as rice or corn, may also be used

Wine

White vs. Red: juice or juice and skin

Yeasts: Ferment when no oxygen around.Saccharomyces species

For white wines, white grapes the skins are removed (“pressing”)

before fermentation

For red wines, red or black grapes are used, and the

skin is allowed to remain during fermentation

For rosé wines, red grapes are used and the juice is allowed to remain in contact with the skins just long enough for a rose or pink color to develop

Yogurt Milk is feremented by a mixture

of Streptococcus salivarius ssp

thermophilus and Lactobacillus bulgaricus (official

name Lactobacillus delbrueckii ssp. bulgaricus).

probiotics

Often these two are co-cultured with other lactic acid bacteria for taste or health effects (probiotics).

These include L. acidophilus, L. casei and Bifidobacterium species.

Acid produced from the fermentation causes the protein in the milk (casein) to coagulate into a semisolid curd

If you want strawberries, you must add them after the yogurt is made

عمل آوردن پنیر

Camembert and Berie: P. camemberti

Roquefort: P. roqueforti