A Series of Blogs

Pores in Granular Starches versi Indonesia

Assalamu'alaikum

Kayanya perlu juga nih sekali-sekali nulis dalam bahasa "Ibu" biar mudah dimengerti hehehhehe , nah sekarang yang mo dibahas ya apalagi... kalo bukan hal penelitian yang sebelumnya udah di-post seminggu yang lalu cuma sekarang bedanya cuma di-bahasa plus mungkin agak lebih lengkap di sini, mudah-mudahan lebih mudah dimengerti .

Penelitian yang sedang dilakuin ampe saat ini topiknya adalah enzim, alpha-amylase, dari mikroorganisme Microbacterium aurum yang mampu mendegradasi -mengolah- pati (pati mentah atau raw starch -granular starch-). Kenapa pati mentah dan kenapa mikroorganisme ini yang digunakan? Satu-satu akan dijelaskan walopun mungkin ga akan terlalu mendalam.

Kenapa pati mentah? karena banyak industri yang menggunakan pati sebagai bahan dasar dalam pembuatan berbagai macam produk terutama produk makanan. Terus apa tuh pati? Pati itu merupakan salah satu sumber karbohidrat yang melimpah dan biasanya tersimpan dalam salah satu organel -bagian dari sel- tumbuhan, amiloplast, dengan bentuk dan ukuran yang bergantung pada jenis tanamannya. Amiloplast ini tidak mudah larut dalam air serta tidak berpori. Dipilihnya kentang sebagai topik utama dikarenakan Belanda merupakan salah satu produsen dan pengonsumsi kentang (soalnya penelitiannya kan di Belanda ), selain itu pula kentang memiliki struktur yang kaku dan bersifat kristalin. Enzim yang ada hingga saat (yang banyak digunakan) adalah enzim yang mampu mendegradasi pati yang telah terlarut, pati yang telah dimodifikasi dan biasanya dimodifikasi dengan menggunakan pemanasan sehingga berbentuk seperti gelatin. Enzim kebanyakannya bekerja maksimum dalam suhu yang relatif menengah (meso). Proses gelatinisasi ini tentunya menggunakan energi yang sangat besar (suhu tinggi) sehingga kemudian digunakan enzim yang termostabil, enzim yang tahan dan dapat bekerja di suhu tinggi, oleh karena itu enzim-enzim seperti ini yang kemudian banyak diupayakan oleh para saintis.

Namun walau demikian, tetap saja dibutuhkan energi yang cukup besar untuk pengolahan pati. Dengan adanya proyek ini, enzim yang mampu mendegradasi pati mentah, diharapkan mampu mengurangi bahkan meniadakan penggunaan suhu tinggi dalam proses pengolahan pati, sehingga energi yang dibutuhkan lebih sedikit dan menghemat biaya.


Nah... alhamdulillah, minggu lalu (sebenernya sih udh dapat sejak akhir taun lalu, tapi dicoba reproducible ato ga)... terbukti dengan jelas lewat SEM... kalo supernatan dari mikroorganisme yang diinkubasi dengan beberapa macam pati mampu mendegradasi pati-pati tersebut, salah satunya dengan terbentuknya pori-pori pada partikel-partikel pati (Gambar atas kiri, kentang yang regular; gambar atas kanan, kentang yang diinkubasi dengan supernatan M. aurum B8.A; gambar kiri, kentang yang diinkubasi dengan supernatan M. aurum DSMZ 8600, mikroorganisme dari supplier bakteri di Jerman). Selain itu, aktivitas yang ada merupakan aktivitas enzim yang unik karena juga udh dikonfirmasi pake mikroorganisme yang sama genus-nya dan ternyata tidak dihasilkan aktivitas yang sama. So... hip...hip... huurayyy... alhamdulillah... bisa juga dapat hasil yang diinginkan walo harus menunggu kurang lebih 10 bulan fiuhh.... tapi belum bisa bernafas dengan lega... masih banyak kerjaan yang harus dituntaskan.... wish me luck sekarang sedang berusaha untuk memodifikasi enzim itu sehingga tau apa yang menyebabkan enzim itu bisa membuat pori-pori.

Pores in Granular Starch

Assalamu'alaikum

Hi...hi... how's going? well... here... at least for these weeks, weather seemed so nice... most of days were sunny even though it's quite cold. But never mind, cos now I will tell another thing which is about my research here, in Groningen. I think I've never tell anything about I will do and have done on my research since I was in April 2007. So... let the story begins...

My research project topic is structure/function relationship of alpha-amylase type of enzymes: new reaction specificities, and functional roles of carbohydrates binding modules. Hohohoho... sounds interesting, doesn't it? well... in short way, it's about enzymes of microorganism's activity on granular starch. And why it's so interesting topic? I will explain it one by one... so it can be understandable as well for anyone who's not in the same subject

My work for more less 10 months was on enzymes of Microbacterium aurum which can degrade granular starch, on potato granules starch as main target. and why do we focus on starch especially on potato granules starch? Short explanation, cos I think most of you know what is starch, starch is glucose polymer which is a long term storage compound present in seed, roots, and tubers of many plants. Starch is stored in amyloplasts (figure above, amyloplast of potato, credit to Wikipedia), which are water insoluble granules that vary in shape  and structure depending on the botanical origin. Potato starch granules are rigid, have a high crystallite and do not possess pores. Therefore, potato starch is rather resistant to microbial degradation at low temperatures. Moreover, there have a few reports about this genus (Microbacterium) on enzymes specifically.

Why are we looking for activity on granular starch at low temperature? As we know, there are a lot of food industries which use starch as a source to get many products from it. And before it was processed into several intermediate products and final products, it was gelatinized by swelling in high temperature. If this step could be reduced from this process, it will reduce of use of energy which is more economize .

So... from my research, I found that culture fluids of M. aurum B8.A can digested granular starch from wheat, tapioca, and potato starch. Although a high level of activity was found with wheat and tapioca granules starch, digestion of potato granules starch was slow. Scanning Electron Micrography (SEM) figures showed the effect of enzyme(s) on granular starch which gave high density pores on granular. Activity on granular starch was compared to other strain of M. aurum (M. aurum DSMZ 8600) as well, and showed that activity on granular starch was only found in M. aurum B8.A.

Figure (Left) untreated potato granules and (Right) after fermentation for 78 hours.

Foggy February

Assalamu'alaikum

Today just like the day before... jumped on the merry-go-round... or you can called it daily routine. This morning when I just woke up from my bed... I think there was nothing special... as usual... cos I really wish there is snowfall... but wish is only wish .... ooops... actually there was snow (I don't remember exactly when it was), but... (there will always a lot of but... ) just only for short time... and it was just wet snow... so.. quite happy and quite disappointed in the same time.

Back to today's story, there were a lot of things happened today start when I was riding my bike to go to my office... it was a little bit cold and little bit foggy, but it always happens here... so... just don't even think about it. Closed to Groningen Central Station, I found that fog was more and more... even more in Haren... I was surprised.... cos yesterday, it was really sunny... really nice day (most of people said like that)... or maybe it happens because of the temperature changing?... maybe or maybe not... I'm not so sure cos here... we can't predict what we will have for weather on next day, it's so unpredictable.

And I don't know why... even though it was foggy... but the rest of the day... I didn't feel any bad mood, I really enjoyed my time (syukur alhamdulillah) and I can sat on the outside building when was coffee time on afternoon (it's not common for me and the other to sit outside when it was cold and gray, except for smokers ). Even one of my colleagues said.. "hey... the smile was back" . Maybe it was because I got good result on one of my research today (alhamdulillah), so... I'm really happy and now I wanna share it... my happiness with all of you.

 Another surprise is (it was started since last week or late)... many plants and flowers are starting blooming... it's a little bit strange cos this month as official is still on winter time is it because of global warming... so weather is changing??? I think so... I heard about it a few times ago. Here is flower picture (right side) which I took in this morning close to main gate entrance of Biological Center, Haren. There are more, but I just can take this one. It is nice, isn't it?